Nuclear threat by Russia

As of writing this article (May 2024), more than two years have passed since Russia’s launch of its invasion of Ukraine (Ukrainian war), showing no sign of the end of the war. One remarkable point about this war is Russia’s frequent nuclear blackmail against the North Atlantic Treaty Organization (NATO) and Ukraine, suggesting the possibility of limited use of nuclear weapons. It made headlines across the world when Russian President Vladimir Putin appeared in a domestic TV program aired in March 2015 on the occasion of one year from the annexation of Crimea and stated that Russia had been ready to put nuclear forces on alert—i.e., ready to use nuclear weapons—during the military operations leading to the annexation.[1] In the ongoing Ukrainian war, Russia is using nuclear threats even more blatantly. On February 19, 2022, Russian forces conducted “strategic deterrence exercise” involving the launch of inter-continental ballistic missiles (ICBMs) and hypersonic missiles,[2] and it was reported on February 27, 2022, shortly after the Russian invasion of Ukraine, Russian President Putin had “ordered his military to put Russia’s nuclear deterrence forces on high alert.”[3]

For more than two years since then, Russian political and military leaders have from time to time used the threat of limited use of nuclear weapons to force NATO and Ukraine to back off. This strategy of Russia, which is to first achieve dominance in the levels of conventional high-severity warfare and limited use of non-strategic nuclear weapons[4] and then stabilize the situation to its advantage by threatening its opponent, is called “de-escalation.”[5] This strategy, when applied to the ongoing Ukrainian war, can be translated as entering into a cease-fire negotiation after cutting off the Crimean Peninsula and the Donbass region from Ukraine.

Having superiority over the opponent in competition by having the intention and capacity to proactively control the escalation ladder—i.e., ups and downs of the situation—is called “escalation dominance.”[6] At the beginning of the 21st century, only a small number of researchers pointed out the risk that Russia might be intending to achieve escalation dominance by deploying military options including non-strategic nuclear weapons. However, following Russia’s invasion of the Crimean Peninsula in 2014, this risk has become increasingly recognized.

As such, Russia has been making de-escalation attempts, not only achieving escalation dominance by possessing non-strategic nuclear weapons but also threatening Ukraine and NATO countries by suggesting the possibility of limited use of nuclear weapons in the event of failed deterrence (Ukrainian war). The ongoing war in Ukraine is an unprecedented case in which a nuclear-weapon state invaded another state using the threat of a nuclear strike, and this posture of Russia to rely on nuclear weapons is understood as being intended to offset its inferiority to NATO in conventional capability.[7]

What is the direction of PLA’s buildup of nuclear capability?

In contrast, China’s nuclear strategy remains largely unclear with little information available. The U.S. Department of Defense (DoD)’s 2023 annual report on China’s military power dedicated only slightly less than 12 pages, out of total more than 200, to the nuclear capability of the People’s Liberation Army (PLA).[8] China successfully carried out its first nuclear test in 1964, but for many years after that it was unrealistic, both economically and technologically, for China to build up nuclear capability comparable to that of the United States and the Soviet Union (Russia). For a country with small-scale weak nuclear capability, escalating warfare to the nuclear level spells a definitive defeat. Therefore, China declared no-first-use (NFU) of nuclear weapons upon becoming a nuclear-weapon state[9] and is perceived to have maintained, until recently, a minimum retaliation strategy, which seeks to achieve strategic deterrence with the minimum necessary capability for retaliation (minimum retaliation strategy).

However, it is believed that China has in recent years been bolstering the nuclear capability of the PLA Rocket Force both in quality and quantity.[10] The U.S. DoD’s 2023 annual report states as follows: “In 2020, the DoD estimated China’s operational nuclear warhead stockpile was in the low-200s and expected to at least double [to more than 500] by 2030. However, Beijing has accelerated its nuclear expansion, and DoD estimates…as of May 2023…that the PRC will have over 1,000 operational nuclear warheads” by 2030.[11] In addition, it is also believed that China has been seeking in recent years to strengthen its readiness posture called “launch on warning (LOW),” intending to attain more reliable nuclear deterrence by enhancing operational combat capability.[12]

Meanwhile, it was revealed in a media report with photos that since June 2021, China had been constructing some 120 ICBM silos in a desert area in Eastern Xinjiang,[13] and it is estimated that the number of ICBM silos has by now reached at least 300.[14] A majority of enhanced nuclear arsenals are ICBMs such as DF-31 and DF-41 missiles, or strategic nuclear weapons such as Jin-class ballistic missile submarines (SSBNs) as well as JL-2 and JL-3 submarine-launched ballistic missiles (SLBMs) loaded on them. In order to threaten its adversaries with the possibility of limited use of nuclear weapons, like Russia is doing now, China would need to have non-strategic nuclear weapons that are limited in their destructive power (low-yield nuclear weapons) and usable for counterforce attacks, not strategic nuclear weapons that would achieve deterrence by punishment with their enormous destructive potential. At the moment, however, China is not in possession of many delivery vehicles available for such purposes.

The aforementioned 2023 annual report by the U.S. DoD cites the DF-26 intermediate-range ballistic missile, which is China’s “first nuclear-capable missile system that can conduct precision strikes,” as a likely vehicle for low-yield nuclear warheads.[15] However, the Stockholm International Peace Research Institute (SIPRI) assesses, based on the sighting of the DF-26 missile at several PLA Rocket Force brigade bases during 2022, that “five or six DF-26 brigades appear to be operational, with around 162 launchers in total, although only about one third of those are assumed to have nuclear mission” and estimates that around 24 of the DF-21 medium-range ballistic missiles are loaded with nuclear warheads.[16] As such, the currently assumed non-strategic nuclear capability of China is limited in scale compared to those of Russia.[17] However, it is also analyzed that conventional short-range ballistic missiles are being replaced by DF-17 medium-range ballistic missiles capable of carrying hypersonic glide vehicles (HGVs),[18] pointing to the high likelihood that China will also build up its low-yield non-strategic nuclear capability going forward.

Conclusion

Looking to the already manifesting nuclear blackmail by Russia in the European theater and an expected further buildup of nuclear weapons by China down the road, if the United States is to respond at the nuclear level to the risk of limited use non-strategic nuclear weapons whether in the East or in the West, highly agile and stealthy sea-based nuclear forces would be a useful option to prevent the adversaries from achieving escalation dominance.[19]

However, the U.S. administration of President Joe Biden canceled the development of a nuclear-armed sea-launched cruise missile (SLCM-N), a program initiated by the administration of his predecessor, Donald Trump, while commencing the deployment of Trident submarine-launched ballistic missiles (SLBMs) armed with low-yield nuclear warheads.[20] Presumably, one reason for this is that in Europe, NATO has insurmountable superiority over Russia in conventional capability and is assumed to be capable of massive retaliation with conventional forces even if Russia dares to launch a limited nuclear strike. Another probable reason is that when we look at Asia, China’s military strategy is basically reliant on conventional capability as exemplified by its anti-access/area-denial (A2/AD) strategy, and unlike Russia, China is not pursuing a de-escalation strategy, which is to force the other side to back off with the threat of use of non-strategic nuclear weapons. It is assumed that for these reasons, the Biden administration sees little need to immediately increase non-strategic nuclear options at this moment.

Currently, China is in possession of various delivery vehicles, i.e., missiles, aircrafts, strategic nuclear submarines. However, unlike Russia, it is not seeking to implement a de-escalation strategy with active use of non-strategic nuclear weapons. In order to make deterrence properly while at the same time avoiding escalation on the part of the United States and its allies, an appropriate strategic direction for China is probably to have sensible discussions without mixing up “missile balance” and “nuclear threshold” and continue to focus, for the time being, on deterrence by means of conventional capability.