The US is stuck with aging nuclear ballistic missile submarines and intercontinental ballistic missiles in a less-than-ideal nuclear posture amid great power rivalry and nuclear uncertainty.
This month, Breaking Defense reports that the Pentagon, due to delays in deploying their successors, is exploring strategies to extend the lifespans of its ICBMs and of the subs that are called, for short, SSBNs. (The SS denotes submarine; the B, ballistic missile; while the N tells us the vessel is nuclear-powered.)
According to Breaking Defense, John Plumb, the assistant secretary of defense for space policy, stated that while the US Department of Defense is dedicated to upgrading its nuclear triad, it is considering strategies to ensure that aging Ohio-class SSBNs and Minuteman III ICBMs remain prepared to respond to conflicts for longer periods than initially expected.
Further, the publication mentions that the DOD is reassessing the US Air Force’s Sentinel program following a 37% spike in program expenses, an overrun significant enough to have qualifed as what is called in Pentagon-speak a Nunn McCurdy breach. It notes that triggering the terms of the legislation in question necessitates action by Defense Secretary Lloyd Austin to determine whether the program can proceed and, if so, to certify its viability.
Breaking Defense says that the US Navy’s shipbuilding has been plagued by systemic issues in its industrial base, resulting in significant 12-to-16-month delays for the upcoming Columbia-class SSBN, built by General Dynamics Electric Boat and Huntington Ingalls Industries.
The report says that the US Air Force’s B-21 bomber remains the only nuclear modernization program that has adhered closely to its planned timeline. Despite the timeliness it notes that, due to inflation, Northrop Grumman has incurred a financial loss of $1 billion on the initial production, a loss that the company is obligated to swallow under the fixed-price conditions of its contract with the Air Force.
Breaking Defense says that a US congressional commission on US nuclear posture cautioned that the Pentagon’s approach for modernizing its nuclear capabilities is based on a “just-in-time” schedule, in which outdated systems are phased out simultaneously with the introduction of new platforms.
The publication notes that the commission proposed various measures to address capacity deficiencies resulting from delays in modernization. One proposed measure is allocating funds for enhancements to Ohio-class SSBNs. Another is distributing existing nuclear warheads among the remaining operational nuclear platforms.
US ICBMs play a complex role in nuclear deterrence, but offsetting their usefulness are vulnerabilities that have prompted debates about their relevance compared with air- and sea-based nuclear weapons.
As for the positives, Asia Times noted in April 2023 that ICBMs act as a “missile sponge” to draw incoming enemy missiles, forcing an adversary engaging in a preemptive strike to use enough missiles to destroy widely-dispersed nuclear silos.
ICBMs also provide a first-strike capability since almost all are on alert and they can launch in minutes.
Further, Steve Fetter and Kingston Reif note in an October 2019 War on the Rocks article that ICBMs act as a tripwire, forcing adversaries to attack the US mainland directly, triggering mutually assured destruction. Fetter and Reif say ICBMs are a backstop to unseen vulnerabilities in the United States’ sea-based nuclear deterrent.
However, they note vulnerabilities in the US ICBM arsenal, namely that they cannot survive a large-scale nuclear attack unless launched in the first 30 minutes between the detection of an incoming missile and impact, with the US “launch on attack” nuclear posture giving only a 10-minute response time.
They also say that an ICBM arsenal is redundant as US bombers and SSBNs are more than sufficient to deliver a second strike. Fetter and Reif also argue that ICBMs offer no unique advantages compared with bombers and SSBNs. Indeed, they say, ICBMs are less flexible than bombers and SSBNs.
Further, Toby Dalton and other writers of a September 2022 Carnegie Endowment for International Peace paper argue that a non-nuclear attack on US ICBMs with hypersonic weapons would present a problem of whether to respond with nuclear retaliation. Also, Dalton and others point out that US ICBMs would have to overfly Russia to hit targets in China, opening the risk of a two-front nuclear war.
While SSBNs are considered the ultimate nuclear deterrent, the long-term US policy of disarmament, increasing costs and technological advancements may gradually call into question their relevance.
In a February 2020 article for the Australian National Security College, James Wirtz notes the American commitment to maintaining an underwater nuclear deterrent due to its survivability, second-strike capability and capability to hold targets at risk after a nuclear or conventional attack.
However, Wirtz points out that the Obama Administration’s declaration of nuclear disarmament as a long-term US objective means that each new generation of US SSBNs has 40% fewer ships than the previous one, with the next-generation US SSBNs, which would be under development in 2060, numbering only seven units.
Wittz’s analysis is that a combination of high costs in deploying a few warheads on an expensive system plus a trend toward nuclear disarmament may undermine support for the US SSBN program, with the Columbia class possibly being the last US SSBN. He also notes that there are talks that the US might have to make do with just 10 Columbia class SSBNs.
Most tellingly, Wirtz mentions the possibility of technological “black swans” upending the relevance of SSBNs. Asia Times noted in March 2023 that advancements in AI, sensor technology, and underwater communication can render the oceans transparent by 2050, meaning that all types of submarines will be detectable regardless of advances in stealth technology.
Asia Times reported in August 2023 that China claims to have developed an ultra-sensitive submarine detector that can detect near-imperceptible bubbles generated by a nuclear submarine‘s hull due to the magnetohydrodynamic effect.
Also, Asia Times reported in September 2023 that China has developed a terahertz device that can detect vibrations as small as 10 nanometers made by a low-frequency sound source in the open sea. Those waves reportedly can be used to detect submarines and identify their model.
Those issues in the US land and sea-based nuclear arsenals may feed into a more significant problem marked by great power competition and possible nuclear proliferation.
In an article this month, The Economist notes that the world may be facing a period of nuclear uncertainty – specifically, that the US and its allies may face uncertainty driven by the Ukraine War and China’s expanding nuclear arsenal.
The Economist also noted stark differences between the Trump and Biden administrations’ nuclear policies, the former advocating for a more robust nuclear posture with the submarine-launched cruise missile nuclear (SLCM-N) program and the latter attempting to cancel that program as unneeded by a more restrained US nuclear posture.
The publication notes that such inconsistency may raise questions about the reliability of the US nuclear umbrella and extended deterrence guarantees.
The Economist says such uncertainty can lead to
- the resumption of nuclear weapons tests by the US, China, and Russia;
- the introduction of new nuclear delivery systems; and
- moves by US allies such as Japan, South Korea, and European states toward acquiring their own nuclear weapons.