The Dangers of a More Crowded Nuclear World

The largest and most destructive nuclear weapons always grab the headlines. Week after week, news items emerge concerning China’s rapid buildup of intercontinental-range nuclear missiles and Russia’s development of “exotic” systems of comparable reach. It makes sense why these long-range strategic capabilities garner so much attention, as they can rain down nuclear warheads on the American homeland from the depths of the Eurasian landmass. But the shorter-range theater nuclear forces of China and Russia have grown steadily as well, and they demand a rethink of US nuclear force posture across the globe.

Even if these shorter-range weapons can’t reach the American homeland, Beijing and Moscow could still wield them to isolate Washington’s nonnuclear-armed allies and then bully them into submission. The ongoing debate about how to adjust US nuclear posture to meet these threats is focused disproportionately on strategic forces. This should change.

Not all nuclear weapons play the same role. Based in the continental United States, America’s strategic forces alone instill in allies little confidence that Washington has their back. America’s theater forces, on the other hand, do a great deal of reassuring, as they are forward deployed in or around allied territory. Their geographic proximity helps convince allies that Washington has them covered.

As China’s and Russia’s strategic forces cast a darkening shadow across the US homeland, allies will wonder whether America’s own strategic forces have been neutralized and, in the long run, will likely come to expect more from US theater forces. Indeed, many already are expecting more from them—or at least, they are sending Washington veiled signals that change is needed to offset the growth in China’s and Russia’s shorter-range capabilities.

An unreliable Washington raises doubts among allies about whether the United States would actually use its forward-deployed forces at all.

None of this should come as a surprise—especially now that the Trump administration has assumed a seemingly adversarial position with its NATO allies. Deterrence experts warn that the most likely pathway to nuclear warfare is not an adversary employing strategic forces in a bolt-from-the-blue attack on the US homeland. Nuclear warfare, rather, is most likely to arise out of a local conventional conflict in the western Pacific or Eastern Europe, where the first exchange of nuclear blows would involve American forces deployed in those respective theaters. An unreliable Washington raises doubts among allies about whether the United States would actually use its forward-deployed forces at all.

Adversaries, too, might question whether an American president would run such grave risks in light of their growing capacity to threaten the US homeland with nuclear devastation. If using theater forces risks sparking a powder trail back to the United States, would an American president openly hostile to allied interests really turn to those shorter-range capabilities in the first place? Would the president risk bringing catastrophic damage upon the homeland for, say, the sake of Tokyo or Tallinn?

Nonnuclear allies across Eurasia are already weighing the prospect of American abandonment. In East Asia, Japan’s prime minister refused to reaffirm her country’s long-standing commitment not to acquire, produce, or even host nuclear weapons, and South Koreans have a growing interest in developing a nuclear capability. With an eye toward the expanding Chinese and North Korean theater arsenals, both Tokyo and Seoul fear there will come a day when the US nuclear umbrella no longer covers them.

The gross disparity between Russia’s large and diverse theater nuclear force and America’s lean and inflexible counterpart has sown anxiety in capitals across the continent.

They look at America’s comparatively bare theater capability in the western Pacific and wonder whether Washington would really respond to a regional nuclear attack with strategic forces. In Europe, allies like Poland, too, have expressed similar concerns. The gross disparity between Russia’s large and diverse theater nuclear force and America’s lean and inflexible counterpart has sown anxiety in capitals across the continent.

These worries are only reinforced by the Trump administration’s self-defeating gambit to wrest Greenland from Denmark. Earlier this month, just before Sweden airlifted troops into Nuuk as insurance against an American land grab, Stockholm’s leading newspaper shockingly called for a joint Nordic nuclear arsenal independent of the United States. Beyond the looming threat of Russia’s theater forces, America itself is undermining its security umbrella, which has long shielded the transatlantic community.

Squeezed between two great nuclear powers, Europe in the long run might decide that, despite its glaring limitations, it has no choice but to field an all-European deterrent. President Trump recently observed that deciding between absorbing Greenland or preserving NATO “may be a choice” he will have to make in the months ahead. With rhetoric like this, it is unsurprising that Britain and France—though armed only with small and inflexible nuclear forces that pale in comparison to Russia’s—appear to be in the initial stages of hedging against a post-American future. Some European commentators have even floated an idea once considered unthinkable in the post–World War II era: that a nuclear-armed Germany might reinforce global order rather than break it.

An Anglo-French nuclear combination would lack the size and flexibility needed to replace the United States and cover frontline countries like Poland in a robust deterrence. But if transatlantic relations deteriorate further, Europe might determine that a relatively weak all-European nuclear deterrent is ultimately preferable to one that has become politically unreliable—even outright hostile. The White House should not take for granted that its European and Asian allies won’t go their own way. Nor should it ignore the tremendous advantages that Washington gains by keeping them under its wing.

The US nuclear umbrella at once helped stave off a third world war with the Soviets while inhibiting the global spread of nuclear weapons—a prospect that threatened to shatter the delicate postwar equilibrium between East and West.

Since NATO nuclearized under America’s umbrella in 1954, Washington has arguably benefited more than its European allies from the present transatlantic system. By reassuring West Germany of protection against Soviet predation and thus tranquilizing Bonn’s urge to go nuclear in the early Cold War, Washington calmed fears of a revived German militarism and suppressed deep-seated rivalries that, in the preceding decades, had engulfed America in two world wars. The US nuclear umbrella at once helped stave off a third world war with the Soviets while inhibiting the global spread of nuclear weapons—a prospect that threatened to shatter the delicate postwar equilibrium between East and West. The “Long Peace” of the Cold War ultimately brought economic prosperity and a dramatic rise in living standards to not only Western Europe but, to a much greater extent, America itself. None of this would have been possible, however, without America anchoring nuclear deterrence in Europe and Asia.

Even after the Cold War ended, the US security umbrella continued to confer considerable advantages on Washington. After the September 11 attacks, NATO allies rushed to uphold their Article 5 commitments—in part to demonstrate their value to American security. Indeed, what’s so maddening about Trump’s coercive campaign against Denmark and Greenland is that in America’s mismanaged wars in Afghanistan and Iraq, the Danes suffered higher casualty rates per capita than the United States. And at the outset of the Iraq invasion, the Danish navy conducted critical intelligence-gathering missions in the Persian Gulf with specialized platforms the US Navy utterly lacked.

It is a historical anomaly that countries like Denmark have so consistently volunteered in service of the dominant world power. But if Washington continues to adopt an adversarial posture, it is difficult to imagine them being so eager to sign up with America again. And this would be unfortunate for reasons nearly every postwar US president well understood.

President John F. Kennedy once warned his national security team that if allies lost faith in America and acquired indigenous nuclear forces, “they would be in a position to be entirely independent and we might be on the outside looking in.” And if Kennedy’s premonition had actually come to pass, a nuclear-armed West Germany could have sown the seeds of all those dire contingencies that Washington so desperately wanted to prevent. A Western Europe lacking the soothing presence of America’s security blanket could very well have reverted to the dog-eat-dog world of the interwar period. A devolution into ruthless economic and military competition would have ultimately precluded America’s ambition to open up and integrate the Euro-Atlantic economies. As Kennedy and most of his successors recognized, it was America’s forward political and military position that protected its economic interests abroad.

A world crowded with more nuclear-armed states is one in which America’s influence erodes and its freedom of action is far more restricted.

The same warning holds true for East Asia. A South Korea distrustful of America’s staying power after the Vietnam War might have refused Washington’s entreaties to cease pursuing nuclear weapons, as it eventually did in 1976. In this alternative future, Washington’s ability to spur and shape Seoul’s democratic transition in the late 1980s would have been severely constrained. One could even plausibly question whether South Korea would have democratized at all if America’s influence had eroded alongside its nuclear umbrella. In this scenario, Japan might also have sprung for its own nuclear weapons to hedge against an American retreat from the region. Instead, Washington’s willingness to reaffirm its nuclear umbrella helped make East Asia’s political and economic liberalization a reality.

A world crowded with more nuclear-armed states is one in which America’s influence erodes and its freedom of action is far more restricted. If Washington does not want to be boxed out of Eurasia, it should think carefully about what a world without the US nuclear umbrella might look like today. It was more than luck and circumstance that saw America and its allies through the Cold War; America’s willingness to do the hard work of reassuring allies by adjusting its nuclear capability to ever-changing threats was crucial.

Such adjustments are no less necessary today with China and Russia than they were with the Soviets. America’s theater nuclear force posture across Eurasia deserves far more attention than it has thus far commanded. To redress the European imbalance with Russia, Washington needs to lead NATO in broadening the range of nuclear response options at its disposal. The foundation already exists to broaden the program through which Washington shares its nuclear weapons within NATO. Both Poland and Britain have purchased from the United States F-35A strike aircraft that can carry US-controlled nuclear bombs. Washington could further collaborate with NATO allies to develop a nuclear-capable missile for these aircraft or a nuclear-capable variant for America’s new theater-based, road-mobile launchers, which currently service nonnuclear missiles.

And to offset the expansion of the Chinese and North Korean shorter-range capabilities, Washington should enable allies in East Asia to operate nuclear-capable delivery systems that, in moments of crisis or conflict, could carry US-controlled weapons. Establishing a nuclear-sharing program in the western Pacific is a step that would bolster regional security, and there is reason enough to believe that Seoul and Tokyo are ready to take it with Washington.

If Washington hopes to forestall another round of nuclear proliferation, it would be wise to adopt a more positive position that reassures allies of its security commitment.

None of these adjustments will be possible, however, unless the United States undoes the damage it is currently inflicting on its alliances. If Washington hopes to forestall another round of nuclear proliferation, it would be wise to adopt a more positive position that reassures allies of its security commitment.

A forward-leaning political and military posture has advanced the interests of the United States since 1945. Land gambits like plans to seize Greenland do not, and Washington would be wise to reverse course. Continuing down the road of bullying allies will not only usher in a more congested nuclear world but ultimately undermine the sinews of American power at home and abroad.

America’s choice is clear. Working with allies to strengthen deterrence is better than being left stranded on the outside of Eurasia looking in.

Kyle Balzer is a fellow at the American Enterprise Institute, where he focuses on nuclear deterrence and strategic studies.