Chinese FOBS and Limited Nuclear Options

In search of "War Termination"

Launching of a Chinese space rocket. Source - CCTV.
Launching of a Chinese space rocket. Source - CCTV.

On 16 October, the US Financial Times published what, in the world of Strategic Studies, was a real bombshell: China’s alleged test of a Fractional Orbital Bombardment System (FOBS) combined with a hypersonic missile. The advantages of FOBS lie in their ability to attack by orbital flight, so that they can describe unpredictable trajectories with a flight profile that makes them very difficult to detect, track and intercept with anti-missile systems or space weapons. In addition to the advantages of orbital flight, in the terminal phase of the attack, the weapon re-enters the atmosphere and strikes as a hypersonic glide-glide missile (HGV). Taken together, the combined characteristics of FOBS and HGVs provide unique capabilities to prevail in a crisis or limited nuclear engagement.

However, this weapon is not a panacea and has the disadvantage that ballistically it is very inefficient; it takes alot of energy to launch a FOBS-HGV, while the same amount of energy used by a rocket in ballistic launch could launch many ballistic warheads. Moreover, FOBS-HGVs are not a “First Strike” weapon that could alter strategicstability between China and the US but are only a weapon for limited engagements and escalation control. Theselimited engagements were formalised in the traditional strategic models of Limited Nuclear Options (LNO), in which strategies, weapons and strike options were designed not for destruction and victory in a full-scale nuclearwar (something impossible in the nuclear world when Second Strike weapons exist), but to provoke “WarTermination” and prevail in the conflict by forcing the adversary to stop hostilities.

As can be seen in the graph, not all Chinese missiles capable of carrying nuclear warheads are capable of reaching the continental United States (CONUS). In fact, only the DF-5 (CSS-4), DF- 31A (CSS-9) andDF-41 (CSS-X-10 not shown) could do so from Chinese soil. Source -
As can be seen in the graph, not all Chinese missiles capable of carrying nuclear warheads are capable of reaching the continental United States (CONUS). In fact, only the DF-5 (CSS-4), DF- 31A (CSS-9) andDF-41 (CSS-X-10 not shown) could do so from Chinese soil. Source –

What is a FOBS system with HGV?

Under such a cryptic name, what is actually hidden is a system that, due to its particular characteristics and flight path, allows it to largely evade missile defence systems and detection systems in service. The basic idea is quite simple, although it hides a great deal of technical complexity when it comes to putting it into practice. FOBS-HGVconsists of a first phase in which the attack vector is launched into orbit, rather than executing a ballistic trajectory attack. Once in orbit, FOBS can make small changes to the orbital celestial mechanics to make unconventionaltrajectories or more accurately match the target. It is called “fractional” because it only makes the fraction of anorbit cycle before re-entering the atmosphere.

A portion of the attack vector then detaches from the spacecraft and enters the atmosphere as if it were a spaceplane (like the old NASA shuttles), as a hypersonic glide missile or as an AMaRV. The difference between an AMaRV and a hypersonic glide missile is the number of kilometres the vehicle flies in the atmosphere. Both an AMaRV and an HGV make flights at speeds greater than mach 5 endoatmospherically. However, an HGV makesalmost all the way to the target inside the atmosphere, while an AMaRV does so only in the terminal phase for a few hundred kilometres. We do not know the details of the type of test the Chinese performed and the number ofkilometres the endo-atmospheric vehicle flew, so it could be either an HGV FOBS or an AMaRV FOBS.

FOBS generally fly in very low orbits, which can be around 150 kilometres above the earth’s surface, which allowsthree things: 1) it helps to evade detection systems, be they early warning radars, infrared detection satellites oroptical orbital tracking systems. 2) It allows for unpredictable trajectories that are very different from traditional ballistic trajectories, forcing the adversary to increase the perimeter of defence. A ballistic or hypersonic attack can only follow direct trajectories from one point to another, like a cannonball. Even a hypersonic glider missile can only make small manoeuvres to evade anti-missile systems but cannot make large detours as it would run out of potential energy with which to execute glider flight. This means that adversary anti-missile systems cannot concentrate on these limited approach routes but must extend defences around the entire national perimeter. 3) The low flight profile of FOBS and the evasive nature of HGVs and AMaRVs allow the strike weapon to have a much higher probability of penetrating and reaching the designated strike target. However, the factors that make the design and commissioning of a FOBS system with HGV or AMaRV so complicated are the following:

  • Firstly, because of the technical difficulty involved in adding to the booster rocket a module capable of orbital flight, with all that this entails in terms of additional fuel, navigation, communications, materials, etc. In this respect, the fuel part is essential, as a large amount of energy is needed to place the vehicle in orbit, as well as to give it the orbital velocity. It is also needed to manoeuvre it, if necessary. All this implies huge amounts of propellant and, consequently, much larger and heavier rockets than an ICBM that can include a multiple independent re-entry vehicle (MIRV) that can even manoeuvre independently during theapproach to the target (MARV).
  • Secondly, because due to the speed that such a vehicle maintains in orbit (about 8 kilometres per second),it must be slowed down for re-entry into the atmosphere, which requires the installation of complex rocket-based braking systems and limits the payload it can carry. This means a smaller warhead and, therefore, less power, although this is not a handicap if, as we shall see, the aim is to control escalation.
  • Thirdly, there is the problem of the cost of the above, which makes it on paper an uneconomical system compared to ICBMs. This is not a trivial issue, as the delivery vehicles that must carry the nuclear warheads and all the necessary equipment to launch them, assign targets, carry out in-flight control, etc.,are extremely expensive.

These three factors speak clearly to the uniqueness of FOBS systems, which are not intended to replace ICBMs ina large-scale nuclear confrontation, but rather to fulfil a much more specialised role related to escalation control, limited nuclear options and war termination, which will be discussed further below.

Finally, there are even legal obstacles to their use, as the People’s Republic of China, like the United States and the Russian Federation, is a signatory to the 1967 Outer Space Treaty. Article IV of the treaty prohibits the placing “in orbit around the Earth any objects carrying nuclear weapons or any other kinds of weapons of mass destruction (…)”. In the past, the Soviet Union has even put a FOBS-type system into service, with the UnitedStates turning a self-serving and rather devious blind eye, claiming that the orbital vehicle was not actually in orbit, but was following an orbit to reach its destination. Nonetheless, it seems clear that, at least during the space phase of the flight, such vehicles are in orbit, which could be used to exert pressure if China were to deploy such vehicles.

Although it is not our intention to do any historical review, the idea of a FOBS is by no means novel. As we havejust mentioned, there were systems in service during the Cold War, specifically one, the Soviet 8F021 (better known by the acronym OGCh) coupled to an R-36O 8K69 rocket. Eighteen units of this system were deployed insilos and were operational between 1969 and 1983, but were subsequently discarded for strategic, technological, operational and economic reasons when their use became unattractive.

It should be noted that FOBS are usually presented graphically as describing a fractional orbit through the South Pole. The reason is that space-based early warning detection systems are focused on detecting ballistic attacks traversing trajectories through the North Pole. SBIRS or older DSP satellites could only detect that a large rocket has been fired but would then not be able to track the attack vector that has been put into orbit following an orbitthrough the South Pole. Once the tracking of the spacecraft is lost, it would not be possible today to track in realtime the orbit and plane changes the spacecraft might make, as it would require a large network of sensors aroundthe globe.

Possible trajectory of a FOBS system from North Korea to Washington DC. As can be seen, far from following the most obvious route, via the North Pole, the possibility of orbiting the planet before executing the re-entry phase would allow the orbital vehicle to follow a trajectory from the South Pole, impossible to detect by existing earlywarning radars and infrared satellites such as SBIRS or the old DSPs. This would impose a number of defensive costs on the US, in addition to opening up a whole range of possible uses, as they would have to install new radars and interceptors with new capabilities. Source - SatTrackCam Leiden.
Possible trajectory of a FOBS system from North Korea to Washington DC. As can be seen, far from following the most obvious route, via the North Pole, the possibility of orbiting the planet before executing the re-entry phase would allow the orbital vehicle to follow a trajectory from the South Pole, impossible to detect by existing earlywarning radars and infrared satellites such as SBIRS or the old DSPs. This would impose a number of defensive costs on the US, in addition to opening up a whole range of possible uses, as they would have to install new radars and interceptors with new capabilities. Source – SatTrackCam Leiden.
As this infographic published by The Financial Times shows, a FOBS system, unlike an ICBM, is capable ofreaching its target along trajectories beyond the control of early warning radars. Thus, even if early warningsatellites could detect the thermal signature of the launch, interceptor missiles, which need to be guided from theground, requiring radars that are tracking the target, would not be able to engage the attacking vehicle in any case. Source - Financial Times.
As this infographic published by The Financial Times shows, a FOBS system, unlike an ICBM, is capable ofreaching its target along trajectories beyond the control of early warning radars. Thus, even if early warningsatellites could detect the thermal signature of the launch, interceptor missiles, which need to be guided from theground, requiring radars that are tracking the target, would not be able to engage the attacking vehicle in any case. Source – Financial Times.

Has China really done a FOBS test?

Before explaining the reasons why FOBS-type systems could be useful again, especially for a regime like China’s, but also for North Korea, we have to clarify that there is by absolutely no proof that Beijing has actually carried out a test with a fractional orbit system.

In fact, the starting signal for reports of Chinese tests was given on 16 October by the US Financial Times, with an article entitled “China test new space capability with hypersonic missile”, signed by Demetri Sevastopulo and Kathrin Hille and which speculated about a test of this type carried out by the Asian country in the summer.Demetri himself shared the news with a link on his Twitter account that same day, accompanying the post with a small thread asking for opinions and help.

At the beginning of the article, it stated, verbatim:

“China test-fired a nuclear-capable hypersonic missile in August that circled the globe before speeding towardsits target, demonstrating an advanced space capability that caught US intelligence services by surprise.”

It also specified, citing intelligence sources, that the missile had missed the target by 24 miles, but still represented a remarkable advance in hypersonic weapons, demonstrating that China was far more advanced inthis field than the Americans believed.

The Chinese regime, for its part, denied that the test was a new type of reusable spacecraft, which is plausiblegiven the speed at which its space programme is moving forward. However, the fact that the launch correspondedto a CZ-2C Long March rocket (flight no. 78) without the announcement being made public also raises suspicions, since the previous and subsequent launches, i.e. nos. 77 and 79 respectively, were publicised. That isassuming that making a launch of this calibre without leaving any evidence behind is feasible. As Daniel Marín points out in the magnificent analysis shared on his blog Eureka:

“It is one thing to launch a secret payload into space, which most space powers do with relative frequency, andquite another to conduct an orbital mission without leaving a trace. And by trail, I do not just mean circumventing US early warning systems, but those of other nations and organisations, as well as the tens of thousands ofwitnesses “armed” with smartphones that exist in China today and make such a scenario almost impossible. In fact, it is so rare that no other similar case is known”.

Of course, China’s hypersonic weapons programme was no secret, and the regime has been at pains to publicise it as much as possible, even parading vehicles in Tiannanmen Square such as the famous DF-17s. However, there are notable differences between the latter and what is proposed here, and it is well known that extraordinary claims require extraordinary proof. So far, not only has there been none of this calibre, but others that would be basic, such as the detection in orbit of the second stage of the CZ-2C rocket or any other debris, have not beencarried out. Similarly, no OSINT analysis seems to have come to light either, through images of Chinese citizens’ mobile phones uploaded to social networks, forums or similar, attesting the launch.

More recently, the Financial Times published a new article, also by Demetri Sevastopulo, in which he spoke of two different tests. One carried out on 27 July, which would include a FOBS- type system, and a second, conducted on 13 August, in which a hypersonic vehicle would have been used, although there is not muchinformation about it.

The various reports and versions have only served to present a confused picture. Still, regardless of whether thesources behind the Financial Times stories were wrong in their interpretation or based on erroneous data, even if the evidence is not what US journalists believe, or if it was all a lobbying campaign for more Pentagon funding, things are not that simple. With or without evidence, the bottom line in the alleged FOBS story is that it makes sense for several reasons that we will be explaining in the following sections.

Although impressive, the size of an ICBM like the Chinese DF-41, with a length of 21 metres, pales in comparison to the more than 30 metres of the CZ-2C rocket needed to launch a FOBS system into orbit. Source - Chen Lan.
Although impressive, the size of an ICBM like the Chinese DF-41, with a length of 21 metres, pales in comparison to the more than 30 metres of the CZ-2C rocket needed to launch a FOBS system into orbit. Source – Chen Lan.

The strategic framework

The exact reasons why China is developing FOBS-HGVs or AMaRVs are not public at this stage. Nevertheless, there is an emerging consensus among the nuclear and strategic studies community that China is shifting from itstraditional conservative deterrent model to one that is much more   ambitious and similar to that of a nuclearsuperpower such as the US or Russia.

The traditional, conservative strategy was based on a so-called Limited Deterrence strategy, which was a Chinese variation of the Minimum Deterrence strategic model, and which over the years was given a multitude of different labels, such as “assured response”, “likely response”, “uncertain response” and many others.

However, China is rapidly expanding the size of its strategic forces. Between 2019 and 2021 China began the formation of several DF-41 mobile ICBM brigades, each year adding several dozen new ICBMs (which in 10 years would give an ICBM arsenal the same size as the US or Russia). To top it off, in 2021 it was discovered that China is building approximately 300 ICBM silos in three different missile fields. All this comes amid intelligence analysis that China will expand its arsenal by 2-4 times its current size over the next 10 years (which would be an arsenal of 1000 or more warheads, a number on par with those deployed and in service in the US). Also to be taken into account are the H-6N nuclear bomber programme, the future strategic stealth bomber, and  the programme to build new ballistic missile submarines and SLBMs that are more modern and capable than those currently in service.

After years of scepticism and labelling as scaremongering the analyses that already warned of China’s nuclear expansion, authors such as Fred Kaplan and Hans Kritensen, who are hardly suspected of being hawks and who are among the doves on nuclear issues, now admit that China is shifting its nuclear strategy to something much more akin to Mutually Assured Destruction.

The reasons why China is now deploying a much more ambitious nuclear strategy than variations of Minimum Deterrence or Limited Deterrence is probably because they have realised that, in the event of a conflict or confrontation with the US, China could deter a large-scale nuclear attack but not a limited conventional military conflict, whether over Taiwan or any other hotspot. Therefore, a quantitatively large arsenal with many ICBMs and SLBMs is needed, plus specific weapons for escalation control such as the nuclear version of the DF-26, hypersonic missiles and attempts to develop FOBS-HGV/AMaRV.

Fiona S. Cunningham and M. Taylor Fravel, in their excellent article “Dangerous Confidence? Chinese Views on Nuclear Escalation“, warned of the danger of a strategic doctrinal gap between China and the US that could lead to a miscalculated war with fatal consequences. In this vein, the Chinese strategic doctrine believed that it could conduct a relatively limited conventional war against the Americans. At the same time, it supported that a nuclear war is not scaleable, and that once the first nuclear use is executed the situation would spiral out of control and there would be a general nuclear exchange. This risk of apocalyptic nuclear exchange helped to avoid crossing thenuclear threshold and keep the conflict contained at the conventional level.

However, if one look at the American strategic doctrine, Cunningham and Fravel pointed out that it is estimated thatconventional warfare could not be controlled too tightly, and from a very limited conventional conflict would quickly escalate into a large-scale conventional conflict. On the nuclear level, the Americans, unlike the Chinese, believe that nuclear war can be maintained with some degree of control, limiting escalation. This has also been describedas “entanglement” by authors such as James Acton.

In this sense, the situation of this doctrinal gap resulted in a situation where on the one hand China could start alimited conventional conflict, believing that it would not go beyond that level because of American fear of a majornuclear war. On the other hand, the Americans escalate conventional conflict to general war, believing that the Chinese would not escalate to nuclear conflict as it would be absurd and because the US enjoys superior escalation control. The Chinese, faced with the prospect of general conventional strategic strikes that would damage dual nuclear-conventional military technologies, might mistake American escalation as a nuclear preludeand      trigger a nuclear response.

Following the argument of the aforementioned authors, it is very likely that Chinese decision- makers realised that in order to wage a limited conventional confrontation with the US (by confrontation we do not mean full-scale war, as long as a confrontation can be in a grey zone or limited conventional military combat without reaching the level of war) they would need a much more extensive nuclear arsenal than the one they had until 2020, since the Americans could escalate the confrontation to a major conventional war without fear of a nuclear war (because the US has Nuclear Supremacy. China needs a strategy to ensure unacceptable damage to the US at the same time as it needs a strategy of nuclear primacy to win in a limited-targetconfrontation.

At this point, it should be borne in mind that each state evaluates the term “unacceptable losses” differently, not only with respect to its own losses, but also to those of its opponent. Even if China were able to keep 60% of its nuclear arsenal (including all the auxiliary equipment necessary for its use) in perfect condition after a conventional attack by the United States, for example, it might consider that this percentage does not guarantee the required level ofdestruction and, therefore, deterrence. Thus, before reaching this extreme situation, the regime might be forced tofind a way to end the war by escalating to nuclear.

In the Chinese case, at least according to authors such as Hans M. Kristensen and Matt Korda, they would stillhave a very limited number of warheads and delivery vehicles (between 272 and 350 compared to 3,570 for the US).With this in mind, it might be sufficient for US SSNs and ASW forces to destroy a significant portion of the Chinese SSBNs. Besides, given that these vessels carry a significant fraction of the delivery vehicles capable of reaching CONUS, their loss would largely end China’s strategic deterrent capability, leading to the scenario discussedabove.

The need for a more ambitious nuclear strategy for China would require not just an extensive nuclear arsenal, with many warheads, ICBMs and bombers, but specific weaponry to fight a limited confrontation. MAD-type strategies deter major conflicts by saturating missile defences and first strikes by deploying a large number of delivery vehicles and warheads, ensuring the survivability of the second-strike arsenal. However, in a limited engagement, the bulk of the arsenals would not be fired in a MAD-type war, but would start with limited nuclear uses of very fewwarheads. In such scenarios, where one or a few missiles are used to cause secondary and peripheral nuclear damage as a warning, missile defences are very useful and could make such a limited strike unfeasible. The only option would be to launch a saturation strike that would cause much greater nuclear damage and escalate to the absurd situation of MAD warfare, causing a “nuclear stalemate”.

For that reason, China is probably developing specific weapons to circumvent anti-missile systems for calibrated and precise use against the US, without fear of provoking a general nuclear exchange. Chinese nuclear expert andauthority on Chinese nuclear issues Tong Zhao, in his article “Managing The Sino-American Dispute Over Missile Defense” states that:

“It is time for the two countries to launch a dedicated effort on this issue because missile defense generates more Chinese suspicion about the U.S. military’s strategic intentions toward China than anything else”.

In other article entitled “What’s Driving China’s Nuclear Build up?”, this author has discussed the shift from aminimalist nuclear policy (of minimum deterrence) to a more confused one, for which there is no official confirmation of objectives yet. As Zhao points out, this would be a response to China’s concern about:

“For decades, China has worried about how U.S. military capabilities—like missile defense and conventional precision strike weapons—could undermine the credibility of China’s capacity to retaliate against a nuclear attack.”.

In this context, it is not surprising that China is rapidly building a new intercontinental missile base, introducing into service more and more DF-41 (CSS-X-20) mobile launchers with a range of up to 12,000 kilometres, increasing the number of SSBNs while developing new SLBMs (JL-3) and implementing ALBM-based nuclear strike capabilityfor its H-6 bombers. Nor is China testing new solutions that allow for a wider range of options.

This is precisely where both “ordinary” hypersonic weapons and the supposed FOBS fit in, since they would makeit possible to increase China’s deterrent capability. In addition, as will be discussed below, to retain control of theescalation, among other things. The consequences are another matter, with  opinions divided between authors such as Jen Judson, who believes that these tests will not trigger a nuclear arms race, and others who are morepessimistic, such as Demetri Sevastopulo.

US and Chinese nuclear arsenals in 2021. The tables drawn up by Kristensen and Korda reflect the overwhelming difference in nuclear warheads and delivery vehicles between the United States and China in favour of the former. However, what they do not show is the difference in terms of quality, where the US weaponry is likely to be far more capable and accurate than China's, making the real difference between the two arsenals greater than the data show and explaining one of the reasons why China isexpanding its Strategic Forces. Source -
US and Chinese nuclear arsenals in 2021. The tables drawn up by Kristensen and Korda reflect the overwhelming difference in nuclear warheads and delivery vehicles between the United States and China in favour of the former. However, what they do not show is the difference in terms of quality, where the US weaponry is likely to be far more capable and accurate than China’s, making the real difference between the two arsenals greater than the data show and explaining one of the reasons why China isexpanding its Strategic Forces. Source –

Escalation control, limited nuclear options and “War Termination”

The point of a nuclear weapon like FOBS-HGV/AMaRV is to impose an unacceptable limited cost on the US to force it to make a “War Termination”. Limited Nuclear Options were developed in the 1970s in the US at the point of the “nuclear stalemate” of Mutual Destruction into which MacNamara’s nuclear strategy eventually drifted after”city avoidance” failed.

If the Soviet Union initiated an invasion of Western Europe, it was not credible that the Americans would trade the destruction of Chicago and New York to defend Hamburg and Frankfurt. In this sense, reaching the level of ageneral nuclear exchange was not worth it to the Americans and would result in a “decouple” or disengagementsituation. Instead of a general nuclear war as in the early SIOPs, an attempt was made to create target packages in which only Soviet economic and military targets would be destroyed to increase the cost of the conflict. All of this without leading to the destruction of cities or the destruction of their strategic nuclear arsenal. Therefore, itwas a limited strategy to impose an unacceptable non-apocalyptic cost.

In these strategies, decision trees were made on the possible evolution of the conflict, and as the Sovietsescalated, a context-calibrated nuclear response was triggered, without executing a nuclear strike against the cities and their strategic nuclear arsenal. In the end, in theory, a “Schelling Point” was reached at which the USSR was not interested in either escalating the conflict or continuing at that level of the conflict, but rather in accepting that a stalemate had been reached, thus achieving “War Termination” and the end of hostilities.

As noted above, the strategic sense of FOBS-HGV/AMaRV would be to be able to threaten to launch a limited nuclear strike against the US, circumventing its current and future anti-missile systems. As Tong Zhao pointed out,the main fear of Chinese decision-makers is missile defences.

In particular, it is believed that the Chinese fear is not absurd and has a real basis. Missile defences are not intended or designed to counter saturation attacks by hundreds of Russian and, in the future, Chinese missiles,but rather that after a successful First Strike, the few surviving missiles and warheads could be mostly shot down, creating a strategic “Window of Vulnerability”. The other is that in a limited exchange, missile defences can be highly effective and useful. Utility in the face of limited options is what induced the UK to have its Polaris systems fitted with the Chaveline bus, to circumvent Soviet anti-missile defences that could have nullified a limited attackby the few Polaris the UK possesses.

In the aforementioned Financial Times article, the author quotes Admiral Charles Anthony “Chas” Richards,current head of USSTRATCOM (United States Strategic Command), who in reference to China’s test asserts thatChina could “now execute any possible nuclear use strategy”. This statement may be somewhat exaggerated, butit is a perfect illustration of what is at stake. Before doing so, however, it is worth briefly reviewing the evolution of China’s nuclear doctrine and strategy to understand exactly where we stand and what Beijing is trying to achieve.

The first thing to be clear about China’s nuclear strategy is that, as Michael D. Swaine points out in “The PLA Navy’s Strategic Transformation to the “Far Seas”: How Far, HowThreatening, and What’s to be Done?”, the first-hand information available to us is practically non-existent. The People’s Republic of China does not make its nuclear strategy public and there are no known documents that set the lines of action to be followed in black and white. Nevertheless, the analyses carried out by experts in the rest of the world are accurate, conjectures based on statements by Chinese military and politicians, studies by Chinese academics and other more or less reliable                            sources.

According to authors such as Chase, Erickson and Yeaw in “The Future of Chinese Deterrence Strategy”, Mao’s dogmatic approach initially prevented any debate on nuclear strategy. The situation would later change and by the1990s some discussions would  focus on the shift from a doctrine of “minimum deterrence”, comparable to that implemented by France with its Force de frappe, to one of “limited deterrence”, an elusive concept whose exact meaning has been a source of fierce debate among scholars and experts. As Alastair Iain Johnston explains in “China’s New “Old Thinking”: The Concept of Limited Deterrence”, there are at least three different sets ofconceptions of what “limited deterrence” might be as the Chinese understand it:

  • Have a small number of nuclear weapons capable of causing unacceptable damage to enemy cities or;
  • An own model based on a small triad (the author calls it a proto-triad) and deliberately playing withambiguity regarding the doctrine of employment or the posture of force, in order to confuse rivals.

Be that as it may, all these doctrines are different from what the Chinese would call “maximum deterrence”doctrines such as those pursued by the United States and Russia, based on counterforce strikes, the possibility oflaunching second and even third strikes, and so on. In fact, although the expansion of China’s nuclear arsenal is a fact and a process underway, there is no agreement on whether it will ultimately lead to seeking parity with theother two major players or whether it will only reinforce this “limited deterrence” capability.

Leaving aside academic debates and following Johnston, one could argue that, to achieve this “limited deterrence” capability, China would need “sufficient tactical, theatre and strategic counterforce and countervaluenuclear forces to prevent escalation from conventional to nuclear conflict”. Even if deterrence were to fail, “this capability should be sufficient to control escalation and force the enemy to de-escalate”.

It will of course seem to many that, once nuclear exchange has begun, escalation to all-out nuclear war is inevitable, so there is no point in pursuing any kind of limited option. This is a recurring idea, but one with little theoretical basis. As Elbridge A. Colby explains in “The Need for Limited Nuclear Options“:

“(…) the notion that any nuclear use would necessarily lead to Armageddon strains credulity. Ultimately, no one in a conflict between adversaries with survivable nuclear forces would have an interest in a large-scale exchange of nuclear weapons, a fact that would provide immensely strong incentives for restraint that must not be ignored (…)”.

Precisely for this reason, the same author, in reference to the United States, states that:

“The United States will therefore want to have ways of credibly threatening to employ its nuclear weapons—and, if need be, of actually employing them—that are potent but that also have limited escalatory implications. In particular, it should be able to use these weapons in ways that are rationally correlated to the provocation or aggression—ways that are neither feckless nor suicidal. The purpose of such options would be to help persuade the enemy that it is better to terminate or at least de-escalate the conflict on a basis acceptable to the United States and its allies rather than to continue along the path he has embarked on.”

This is precisely what China is looking for and what systems such as FOBS, which allow for certain guaranteeswhen it comes to successfully launching a very limited attack against CONUS, are for. Thus, if at some point the Asian country ends up having local conventional capabilities superior to those of the United States, it could take advantage of this window of opportunity to achieve its strategic objectives. Hence, forcing its enemy to refrainfrom pursuing the war in the long term or to escalate to an all-out nuclear war through a very limited nuclear strike.

An interesting paradox here is that, in certain scenarios, a limited nuclear strike might appear much less threatening (i.e. less escalatory) than a large-scale conventional strike. Consider that the effects of a mini-nuke or a nuclear warhead of varying power used at minimum yield against a well-chosentarget send a perfectly clear message that seeks to stop or de-escalate the conflict. In contrast, launching large-scale conventional operations, striking at the same time very different targets throughout the enemy’s territory and potentially taking out critical facilities or infrastructure, is an invitation to the opponent to cross the nuclear threshold to end them.

Furthermore, one has also to bear in mind that not all latitudes make as clear a distinction as we do betweenconventional and nuclear conflicts. This clashes with our vision, marked by the work of authors such as Beaufre in “Introduction to Strategy”, who said that “[because of] this double characteristic (power and range), the atomicweapon provokes a completely new phenomenon: there is no longer any relationship between power and mass”. However, this seems to be the case for the Chinese and Russians, who see it rather as all part of a continuum in which the nature of warfare does not change. Consequently, doctrine and weaponry must be perfectly adapted to the need to traverse this continuum. For this to be possible, between conventional war and all-out nuclear war, there must be spaces in between. Spaces that are built with the right doctrine and the right means.

For such “limited nuclear options” to be implemented, a number of conditions have to be met, which are notalways technically straightforward. The main one is that the weaponry used must be capable of hitting a targetwithout the need for a large-scale attack. To do so, it must be able to overcome the enemy’s defences. Of course, whatever these defences may be, they can be overwhelmed by the mere accumulation of offensive assets, but in that case the escalation to full-scale warfare would be unstoppable and China would be subject to massive retaliation. So, the only viable option is to design systems such as FOBS that offer some alternative possibilityand that, even if used in very small numbers, can hit a target with certain guarantees.

The other side of the coin, and also one of the reasons why a FOBS system might be attractive to China, is that its deployment would automatically impose defensive costs on the United States. The latter would have to field new systems capable of covering unexpected avenues of approach. Moreover, if necessary, to develop interceptors capable of dealing with hypersonic vehicles returning on trajectories that are very depressed relativeto ballistic missiles.

However, based on the number of weapons and delivery vehicles provided by authors such as Kristensen and Korda, China is still far from reaching an “ideal” state in which it is invulnerable to a nuclear first strike. Besides, not only is its triad still vulnerable even to conventional attacks (without the need for a nuclear first strike) butlacking the means to implement flexible responses. Also, it is unable to maintain control of escalation during thetransition from conventional to nuclear engagement. It is therefore logical for Beijing to push not only for thedevelopment of hypersonic vehicles, but also for more complex options such as a FOBS. This would make perfect sense:

  • Escalation control weapon;
  • Tool by which implementing Limited Nuclear Options;
  • A way to impose defensive costs on the United States.

What cannot be, as has been claimed by the mainstream press, which in many cases has not even distinguishedordinary hypersonic missiles from a FOBS system, is that the alleged Chinese FOBS is considered a systemsuitable for launching a large-scale attack capable of annihilating

the United States. In fact, FOBS would not be valid either to launch a first strike to dismantle the US nuclear network, preventing it from launching its retaliatory strike, or as a retaliatory weapon.

China's hypersonic weapons programme is advancing at full speed. However, such systems are not a panaceaby themselves, as explained earlier. Source - CCTV.
China’s hypersonic weapons programme is advancing at full speed. However, such systems are not a panaceaby themselves, as explained earlier. Source – CCTV.

Practical example: the invasion of Taiwan

The theoretical explanations that have been just offered will be better understood when applied to a scenario that any reader can envision in his or her head. The most obvious, when talking about China, strategic deterrence,escalation control and the role of a FOBS-type system, is that of a war over Taiwan.

For years now, as tensions around the island nation have been rising, with numerous overflights by Chinesebombers and fighter-bombers, increasingly aggressive statements and the exponential growth of China’samphibious fleet, fears of an invasion attempt have been growing. In reality, beyond the undeniable capabilities of the Republic of China’s (Taiwan) armed forces, what is really holding back the communist regime is the extended US deterrence. Indeed, the great power is increasingly involved in Taiwan’s defence, not only through the supplyof advanced weaponry, but also through a large and continuous naval deployment in the region, in addition to theamphibious, air and land forces spread across the numerous bases the United States maintains in the Indo-Pacific.

US involvement is a brake on the People’s Republic of China not so much because it cannot inflict defeat in the early stages of a conflict through the combined efforts of its navy, air force and missile force and even seize the island, but because of the possibility that the United States, far from writing off the conflict, might decide tocontinue the war from a distance and indefinitely.

In this case, the effects on the Chinese economy (and let us remember that, as in any dictatorship, the stability of the regime depends directly on the health of the economy) would be dramatic. Undoubtedly, the country wouldbe subjected to a naval blockade that would

prevent it from transporting the essential inputs that its factories need to continue production, as well as from shipping them out afterwards. Let us remember that China, disadvantaged by geography, is forced to move huge quantities of raw materials, later transformed into finished products, through straits such as the Straits of Malacca and Japan, oceans such as the Indian Ocean, and seas such as the Red Sea and the Arabian Sea. All these points can be exploited by the US Navy, the USAF and US allied forces (this is where the value of initiatives such as the Quadrilateral Dialogue or alliances such as AUKUS can be seen) to block Chinese SLOCs (Sea Lines ofCommunications) and thus their manufacturing activity.

It is clear that the People’s Republic of China cannot risk being dragged into such a scenario, nor does it have the means to overcome a determined naval blockade by the United States and its allies. Nor to circumvent it. The only alternative for the regime is therefore to find a way to end the conflict once its strategic objectives have been achieved in the early stages and before the US can mobilise its full potential. This is where FOBS-type systems come into play, since their characteristics would make it possible to launch a selective attack. For example, hitting a military base, a logistics centre or a US communications hub that without the ABM systems, designed preciselyagainst limited ballistic attacks (in terms of numbers and possible trajectories) by powers such as North Korea or Iran, were able to do their job.

Such an attack would be sufficient to demonstrate China’s determination to retain control of the territories it hasgained even at the risk of provoking a full-scale nuclear war. However, the main objective of the action would actually be to end hostilities, which is only possible if they retain control of the escalation. That, and no other, will be the raison d’être of the Chinese FOBS system, if it ever enters service.

Launch of an SM-3 Block IIA from the USS John Finn as part of the Aegis Ballistic Missile Defence System tests.As good as this system is, it is still insufficient to deal with the combination of FOBS and HGV. Source - MDA.
Launch of an SM-3 Block IIA from the USS John Finn as part of the Aegis Ballistic Missile Defence System tests.As good as this system is, it is still insufficient to deal with the combination of FOBS and HGV. Source – MDA.


The People’s Republic of China is amid an unprecedented process of expanding its nuclear arsenal. Thisexpansion is not only quantitative, affecting the number of warheads and delivery vehicles, but also qualitative,introducing more modern and capable systems. Moreover, the improvements are not only incremental, i.e. in termsof numbers (greater range, greater precision, greater payload capacity…) compared to those they are to replace, buton the contrary, they are systems with new capabilities, as is the case with the recently tested FOBS, if it everenters service.

The raison d’être of Fractional Orbit Bombardment Systems lies in their ability to circumvent strategic defences, focusing on this case in the US defences. However, due to their high cost, they are not suitable for large-scale nuclear exchange, while ICBMs have a better cost/capability ratio. Nevertheless, these systems are optimal whenit comes to increasing the options for limited nuclear warfare, pursuing “War Termination” and, in short, controllingescalation.

To conclude, given that China needs to be able to maintain control of the escalation, especially in the event of a limited conflict over Taiwan, and even if the test we have discussed did not actually correspond to a real FOBS, itseems likely that Asian country will end up opting for such a system.


Be the first to comment

Leave a Reply

Your email address will not be published.