President-elect Biden has signaled that his administration will review the U.S. nuclear posture with an eye to revitalizing strategic arms control negotiations and potentially reducing the number of weapons in the arsenal.
One item certain to receive scrutiny is the plan to replace 400 Minuteman III intercontinental ballistic missiles (ICBMs) sitting in hardened underground silos at bases in the upper Midwest. The missiles were first deployed in 1970, and are expected to exceed their reliable service life in 2030.
That leaves ten years in which to develop and begin fielding a successor called the Ground Based Strategic Deterrent. Some prominent Democrats, including House Armed Services Committee Chairman Adam Smith, think the new weapons cost too much, add little to deterrence, and could be destabilizing in a crisis because they are easily targeted (their locations are well known).
These arguments have been around for some time and did not convince the Obama administration to deviate from its plans to replace Minuteman III.
An artist's conception of the Columbia-class ballistic missile sub. U.S. strategic submarines are ... [+]
In fact, all three legs of the nuclear arsenal—bombers, ballistic missile submarines, and land-based ICBMS—are due to commence replacement toward the end of this decade. For instance, the lead vessel in a new “Columbia” class of ballistic missile subs is scheduled to conduct its first deterrence patrol in 2031.
It is not unreasonable for critics to question whether the U.S. really needs all 1,550 long-range nuclear warheads permitted under the strategic arms reduction pact called New START that President-elect Biden says he will seek to extend.
However, what matters in nuclear deterrence is not how many weapons a nation possesses before war begins, it is how many remain after a surprise attack. The threat of severe retaliation is what deters potential aggressors from launching an attack in the first place.
If Russian or Chinese leaders thought they could disarm the United States in a first strike, they would have powerful incentives to do so, because America’s strategic arsenal is an existential threat to their survival.
That logic would be especially likely to prevail in a crisis, for example in a military confrontation over Taiwan. If Beijing believed a nuclear exchange was imminent, it would have good reason to contemplate ways in which a surprise attack on the U.S. nuclear force might blunt or negate any retaliation.
If that scenario were to arise today, Chinese leaders would need to be delusional to actually launch such an attack. About 70% of U.S. strategic warheads are carried on 14 Ohio-class ballistic missile subs that can’t be targeted when they are at sea. Nuclear bombers can be dispersed to scattered locations in a crisis, and Beijing could have no assurance U.S. ICBMs wouldn’t launch before being destroyed in their silos.
So there is no rational logic to launching an attack, even in an extreme crisis. The U.S. nuclear triad was conceived with such thinking in mind.
Critics can build a plausible case that the 400 nuclear warheads in a modernized ICBM force aren’t needed to deter under current circumstances.
But now change one pivotal assumption in U.S. nuclear strategy. Imagine that sometime between now and 2070 Russia or China figures out how to track U.S. ballistic missile submarines. Submarines have numerous “signatures” that potentially reveal their location—acoustic, magnetic, thermal, etc.—and it is conceivable that at some point over the next five decades, adversaries might discover how to find the U.S. undersea deterrent.
If that actually happened and the U.S. had abandoned its land-based ICBMs, an enemy could effectively disarm the U.S. in a surprise attack on less than two dozen targets. The targets would include a dozen Columbia-class subs destined to replace the Ohio class, three strategic bomber bases, and a handful of command-and-control locations such as U.S. Strategic Command headquarters near Omaha.
If the attacker were China, it might elect to deliver two warheads against each of these targets to assure a kill. That would require less that a fifth of the long-range weapons in China’s present strategic arsenal.
The point here is not that the oceans are about to become transparent or that Chinese leaders would willingly assume huge risks in a future crisis. The U.S. Navy is spending copious amounts of money to assure its subs cannot be targeted in a crisis, and Chinese leaders are generally viewed as risk-averse.
The point is that we really can’t predict what the future holds during a period of unprecedented technological change. Tracking U.S. ballistic missile subs may be impossible today, but what about in 2050?
There was a trillion-fold increase in computing performance during the 60 years ending in 2015. What if we see similar gains in the 60 years between now and when the Columbia-class subs conduct their final deterrence patrols?
During that time, a country like China will likely deploy multiple constellations of ocean reconnaissance satellites, hundreds of long-endurance maritime patrol drones, advanced sensors scattered all over the world, and a resilient global network capable to delivering virtually unlimited computational power anywhere for signal processing.
Does that mean U.S. submarines will cease to be stealthy? Probably not, but if they did become attackable the absence of a U.S. ICBM force would greatly simplify the targeting challenge of a nuclear aggressor bent on disarming America.
That, in the final analysis, is why the U.S. must proceed with plans to replace the aging Minuteman III ICBM force. It is a hedge against unforeseen weaknesses in the other legs of the nuclear triad that might occur is coming decades, making a surprise attack more likely.
As Joe Biden has long recognized, arms control can play a crucial role in reducing the incentives to nuclear aggression. But whatever size arsenals negotiators agree on, there can be no doubt about the survivability of U.S. retaliatory capabilities. Having a resilient, reliable ICBM force will likely remain central to that requirement.
Several contributors to my think tank are engaged in work on all three legs of the nuclear triad.
