WASHINGTON, DC – As Chinese President Xi Jinping’s first summit with US President Donald Trump takes place at Trump’s luxurious Florida estate Mar-a-Lago, at least part of the discussion will invariably focus on one of the world’s most impoverished places: North Korea. Despite more than two decades of on-again, off-again negotiations, North Korea’s nuclear weapons program is pushing the world toward a strategic watershed much like the one that the West faced 60 years ago, when the United States and the Soviet Union faced off against each other in Europe.

The US and its allies successfully navigated the challenge of Europe in the twentieth century without war. But to achieve comparable success in East Asia today, Trump must persuade Xi to adopt a different policy toward North Korea.

When the US and the Soviet Union became rivals after World War II, each had a way of deterring the other from attacking. The Soviet Union had – or was widely believed to have – a large advantage in non-nuclear forces, which the Kremlin could use to conquer Western Europe. The US, with its monopoly on nuclear weapons, could launch a nuclear strike from Europe on the Soviet homeland.

Then, in 1957, the launch of Sputnik made it clear that the Soviet Union would soon be able to deliver a nuclear strike on the US mainland, calling into question the effectiveness of American deterrence. Was it credible that, in response to an attack on Western Europe, the US would make war on the Soviet Union, thus inviting a nuclear attack on its own territory? America and its allies had four possible solutions to this novel and dangerous problem: preemption, defense, proliferation, and deterrence.

Preemption – an attack on the Soviet Union’s nuclear weapons – would have started WWIII, a distinctly unappealing prospect. And, as the Soviet nuclear arsenal grew, the US government ruled out defense against a missile attack: because it could not deflect every incoming nuclear explosive, it would be safer if neither side tried to build ballistic missile defenses. President Richard Nixon’s administration therefore negotiated and signed the 1972 Soviet-American Anti-Ballistic Missile (ABM) Treaty, effectively banning such systems.

The third option, acquisition of nuclear armaments by potentially threatened countries, was based on the assumption that a government would be willing to use such weapons to defend its own country, if not another one. French President Charles de Gaulle invoked this logic to justify his country’s nuclear weapons program, although he also had other reasons for wanting France to join the nuclear "club.” By this logic, however, West Germany, too, needed a nuclear arsenal; and, given Germany’s twentieth-century history, no one, least of all the Germans, desired such an outcome.

So the West opted to reinforce the status quo, with the US seeking to enhance the credibility of its policy of deterrence in Europe by stating, publicly and frequently, that it would indeed defend its allies, despite the risk that this would lead to an attack on its own territory. The US backed up its stance by deploying nuclear weapons on the European continent, and by stationing troops on the front lines in Germany as a "trip-wire”: an attack there would trigger US participation in any war the communist side might begin. This strategy worked: for whatever combination of reasons, the Soviet Union never launched a westward attack of any kind.

Six decades later, a similar challenge looms on the Korean Peninsula. Since the end of the Korean War in 1953, a US military presence has helped deter a North Korean attack on the South, while the communist North has deterred the US as well: its massive artillery deployments along the demilitarized zone dividing the peninsula could devastate South Korea’s capital, Seoul, with its ten million people, in retaliation for any US attack.

North Korea’s nuclear weapons program threatens to upset that balance, by giving its regime the capacity, through the long-range ballistic missiles it is testing, to strike the West Coast of the US, thereby raising a new version of an old question: would the US risk Los Angeles to protect Seoul? The US and its Asian allies have the same four options as the Atlantic Alliance had 60 years ago.

They can attempt to live with North Korean long-range nuclear missiles, relying on deterrence. Peace, and the safety of millions of Americans, would then depend on the prudence and rationality of North Korea’s 33-year-old dictator, Kim Jong-un, a young man with a taste for grotesque executions of family members and close associates.

In the past, such an outcome has seemed unacceptable to US national security experts. In June 2006, William Perry, a former defense secretary, and Ashton Carter, a future one, argued in The Washington Post that if North Korea deployed on its territory a nuclear-armed missile capable of hitting the US, the US should attack and destroy it.

But, like the status quo, attacking the North’s nuclear arsenal would carry enormous risks. Such an attack would likely trigger a second Korean War. The North would surely lose, and the regime would collapse, but probably not until it inflicted terrible damage on South Korea, and perhaps also on Japan.

Having withdrawn from the ABM Treaty, the US has already begun to deploy missile-defense systems, with the hope of defeating a small-scale nuclear assault (though not a massive attack of the kind Russia could launch). This option, too, carries grave risks. As the North Korean nuclear arsenal grows, the effectiveness of missile defense will diminish. Even one nuclear explosion in the US, South Korea, or Japan would be a catastrophe.

Michael Mandelbaum is Professor Emeritus of American Foreign Policy at The Johns Hopkins University School of Advanced International Studies

Copyright: Project syndicate