Holding ICBMs at risk as a driver for U.S. force augmentation

As stated earlier, U.S. policy is to hold at risk critical assets and installations most valued by enemy leaders. An adversary’s nuclear forces might well fall into that category. In the case of China’s ongoing ICBM ramp up, the U.S. must decide whether and how to hold such forces at risk. One alternative is a force augmentation involving additional U.S. ICBM warheads.

Whether to hold the entire Chinese ICBM force at risk, some portion of it, or none of it is an open question. Indeed, U.S. policy specifies a role for counterforce targeting “only to the extent practicable or feasible.” For example, Russia’s 1990s initial deployments of mobile ICBMs made these forces more difficult to target. The policy seemed then to suggest: “OK to continue to try to hold mobile ICBMs at risk, but plan to do so with available forces and don’t expect a ramp up that would exceed existing limits in order to meet a more demanding requirement.” U.S. strategic force augmentation, depending on whether any agreed limits on forces are put in place after New Start expires, may require adjustment to this policy.

There is a benefit to the U.S. having a capability to hold some portion of China’s silo-based ICBMs at prompt risk. And not just for damage limitation. The Chinese should come to understand, as the Russians eventually did, that these systems are not being given a “free ride,” thus providing some disincentive to the ongoing ramp-up. In light of possible Sino-Russian coordination, this would require some augmentation of U.S. ICBMs (and potentially SLBMs). Depending on assessment of the likelihood of various levels of cooperation, this shortfall could be redressed with a smaller or larger force augmentation. Effective U.S. ballistic missile defenses could lower augmentation needs as could, potentially, additional forward deployments of existing, and potentially new types of U.S. non-strategic nuclear forces.

How many warheads to upload?

In the near term, U.S. forces could be augmented by uploading reserve warheads to existing delivery systems. Re-MIRVing Minuteman III and, at some cost in responsiveness, uploading warheads to fill currently-unoccupied slots on the Trident D-5 SLBM could add several hundred additional warheads to the deployed force. Ensuring that sufficient reserve warheads are available (and not placed in the dismantlement queue!), and timely provision of tritium and limited-life components (e.g., gas bottles, neutron generators) to activate reserve warheads is essential. Once activated, timelines for weapons upload will vary depending on the delivery system—days to weeks for bombers, weeks to months for the subs, and one to three years for ICBMs. To be sure, uploading does add some operational inefficiencies. Still, this is not an insignificant force augmentation capability by any measure.

How many warheads might need to be uploaded? China may add about one thousand ICBM warheads (350 silos) by 2035 with about half fielded by 2030. If upload is primarily to hold at risk some portion of China’s silo-based ICBMs, options could include—700 additional warheads (2 per silo), 350 additional warheads (one per silo), or quite possibly fewer depending on willingness to accept risk. Two on one targeting will be seen as, and indeed is, excessive. Given this admittedly rough estimate and assuming that Russia remains at roughly current levels, in the nearer term at least no more than a few hundred additional ICBM warheads could meet “two peer” deterrence needs.

When to upload?

One study argues to upload reserve warheads starting in 2026 when New START expires. This may be premature assuming a hedge upload capability that can be fully executed in one to three years, well before China’s new ICBMs become fully operational in 2035. If this estimate holds, there is more time to work the “two peer” problem while pressing to eliminate any force upload capability shortfalls. And what if, after New START expires, Russia presses to extend limits in some form simply to constrain any U.S. upload so that China might catch up? Would the U.S. reject such a proposal from Russia? Pressing for an earlier than needed upload, possibly via a unilateral decision not to seek to extend arms limits, would be contentious and has potential to upset the so far bipartisan consensus on modernization. On the other hand, being skeptical of intelligence assessments is prudent policy; we must consider that China could accelerate its buildup. Uploading sooner hedges that risk.

If one is optimistic regarding the 2035 estimate, prudent and timely U.S. force augmentation would begin in the 2030 timeframe. This would provide time both to build a political consensus for augmentation without jeopardizing the ongoing modernization program, and to fix any force upload shortfalls. It would also provide time for other strategies (e.g., diplomacy, arms control, U.S.-China dialog on strategic stability) that, while perhaps unlikely to succeed in the current security environment could, if they did, conceivably mitigate if not alleviate upload needs.

Some further thoughts on deterrence

The most likely path to peer nuclear conflict involves escalation from an ongoing regional conventional conflict. Increased forward-deployment of U.S. conventional forces could help to deter such conflict in the first place by the ability to bring force to bear more quickly and reduce reliance on vulnerable reinforcement routes. The goal is to prevent faits accomplis. In recent years, progress has been made in NATO Europe, but more could be done there and in Asia. In addition, conventional deterrence could be strengthened by ensuring that weapons and command and control assets are sufficiently hardened to moderately severe nuclear environments, and that the U.S. regional commands, supported by Strategic Command, adapt their planning to fight the war once nuclear weapons are introduced to the conventional battlefield. Additional deployment of new or existing types of U.S. non-strategic nuclear forces, to include a modern nuclear, land-attack sea-launched cruise missile (SLCM-N), would bolster deterrence and help reduce the need for ICBM warhead augmentation.

Conclusion

The Biden team, if it is not already doing so, should, with urgency over coming months, establish a DoD-led process to review the Russian and Chinese nuclear programs, their potential for acceleration, the implications of Sino-Russia condominium in the nuclear arena and the status of U.S. force upload capabilities, and develop a set of response options for Presidential decision. At minimum, a decision is warranted to ensure a viable, executable option to field a few hundred additional ICBM warheads to meet emerging deterrence needs in the 2030 timeframe.

I would like to acknowledge very useful discussions with Frank Miller, Keith Payne, Brad Roberts, and Rob Soofer in preparing this paper. Recommendations and conclusions are my own.

John R. Harvey, Ph.D., served in senior posts in the Departments of Energy and Defense overseeing U.S. nuclear weapons policies and programs including, from 2009-13, as Principal Deputy Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs.

This article was first published by RealClearDefense.

Image: Shujaa_777 / Shutterstock.com