Does America Need More Nuclear Weapons, Or Is More Not Necessarily Better?

Once again, a siren call is being heard for the United States to increase the size of its strategic nuclear forces. This call has recently come from no less than President Trump. He has loudly proclaimed that the United States should leave behind the self-restraint of President Obama and his predecessors in this important arena. Instead, he has said, his administration should pursue “nuclear supremacy” over its adversaries by greatly strengthening and expanding our nuclear capability. The question needs to be asked: Is Trump putting forth a wise idea or does it fail to make sense?

This question needs to be addressed not with flamboyant rhetoric and bluster, but through penetrating analysis of the complex issues that inevitably arise when nuclear forces are addressed. Decades of experience show that U.S. nuclear forces should be sized through a careful process of reasoning and calculation that focuses intently on the explicit strategic goals these forces are to pursue, the deterrence functions they are to perform in peacetime, and the military missions that are expected of them in wartime. Over the years, the Pentagon has built a family of formal methodologies, such as the “arsenal exchange model”, that enable planners and analysts to create quantitative estimates of how many nuclear forces are needed to survive a surprise nuclear attack, to retaliate decisively against a wide spectrum of enemy targets, and to deter other nuclear powers in a post-war setting. Many analyses using these methods have underscored the need for a large and diverse U.S. nuclear posture, but they also have concluded that there are finite limits on the number of launchers and warheads that are needed in order to fulfill their strategic purposes. Once these limits are reached, additional forces would serve no useful purpose. In this case, more would not be better, just more expensive.
 
With this framework in mind, the adequacy of today’s U.S. nuclear posture can be gauged along with proposals for enlarging it. As military experts know, the United States already possesses a sizable nuclear “triad posture” — that is, a three-legged posture — of about 800 launchers and 1550 warheads, the number permitted by the New START Treaty. This triad is composed of 450 Intercontinental Ballistic Missiles (ICBMs), 14 SSBN submarines each of which can carry up to 24 Submarine-Launched Ballistic Missiles (SLBMs), and 90 bomber aircraft made up of 20 B-2s and 70 B-52s. This posture today costs about $20 billion per year. When New START was signed seven years ago, the Pentagon expressed satisfaction that this triad posture would be large enough to meet America’s enduring military requirements while preserving essential equivalence with Russia. But Trump disagrees with this judgment.

Trump has not said how much he would enlarge the triad, but a plausible guess is 25–30%. If so, the Pentagon would acquire about 100 more ICBMs, 4 SSBNs with 96 SLBMs, and 25 bombers. The result would be a new, bigger triad of about 1000 launchers and 2000 warheads. The effect would be to overthrow New START, thereby either allowing the Russians to pursue their own buildup or requiring a new negotiation that elevates allowable nuclear weapons on both sides. Buying these new weapons would require the Pentagon’s nuclear budget to be increased by about $5–10 billion per year, about 25–50% above current spending in 2017, thereby reducing money that can be spent on conventional forces, their modernization, and their readiness. The strategic consequence of spending more money on nuclear forces thus is less money available for conventional forces, which today badly need improving in a host of areas.

Would these new nuclear weapons produce strategic dividends that are worth the budget cost, the diversion of resources within the Pentagon’s budget, and the negative impact on future START negotiations with Russia? A political argument in their favor is that they allegedly would bolster America’s muscular reputation on the world stage. The counterargument is that because the United States is already a well-recognized superpower, these new weapons would further improve its credibility and influence only at the margins. The North Koreans, for example, already have plenty of reasons to be scared of U.S. nuclear power. Ditto Iran, China, and for that matter, Russia. Fielding additional U.S. nuclear weapons likely would not materially enhance America’s already-formidable reputation in the political and diplomatic arenas. This reality throws revealing light on Trump’s quest for nuclear supremacy. The United States already enjoys decisive supremacy over China and North Korea. If it seeks numerical supremacy over Russia, the Kremlin almost certainly would enlarge its own nuclear posture by an equivalent amount if for no other reason than to prevent the United States from appearing superior to it.

As implied by Trump and his supporters, a military argument for these new weapons is that they allegedly would enhance America’s ability to perform retaliation and strike missions in an actual nuclear war with Russia. While this is numerically true, the larger truth is that the current triad is already large and diverse enough to absorb a surprise attack and retaliate with devastating effects: a conclusion that stands up when the issue is examined using the arsenal exchange model and other analytical methods. The following table shows the unwinnable folly of a U.S.-Russian nuclear war and a core reason why mutual deterrence remains firmly intact today. But it also illustrates that if such a war occurred, a surprise Russian nuclear attack would leave fully 1,000 U.S. nuclear warheads surviving, principally SLBMs and bombers. The United States could retaliate by striking Russia with 500 warheads, enough to destroy most urban areas and major military installations, thereby leaving few additional Russian targets worth shooting at. In this event, the United States would still possess a post-war reserve of fully 500 warheads, plenty enough to achieve post-war deterrence of Russia, China, North Korea, and Iran or any other country that might possess nuclear weapons. For this reason, the current U.S. triad does not need more launchers and warheads to carry out peacetime deterrence, its wartime missions, and its targeting strategy. The current triad of 800 launchers and 1550 warheads passes the “How much is enough?” test by a solid margin, and more weapons would be mostly superfluous.

Strategic Nuclear Warheads: Impact of a Nuclear War with Russia
(Illustrative)

U.S. Warheads Russian Warheads
Peacetime Posture 1550 1550

Remaining Warheads After 1000 500 
Russian Surprise Attack on U.S.

Remaining Warheads After U.S. 500 200 
Retaliation Against Russia

Strategic Result: Both the United States and Russia suffer cataclysmic damage, and neither side wins a nuclear exchange.

The bottom line thus is twofold. Acquiring these new launchers and warheads in theory might add somewhat to America’s political reputation and to its nuclear war-fighting options. But when this idea is seen in a larger context, it comes across, at best, as providing strategic benefits that are more marginal than decisive and, at worst, as being inconsequential and even counter-productive. All things considered, the United States likely would be better off by keeping the triad at its current size while performing two better courses: modernizing the triad with new SLBMs, bombers, and ICBMs when they become available, and strengthening America’s arsenal of defense interceptors capable of shooting down enemy nuclear missile attacks on Europe, Asia, and the continental United States. Living with the current triad while gradually improving it may sound unglamorous to proponents of enlargement, but it falls on the wiser side of good judgment.