President Donald Trump’s statement over the weekend that the US plans to withdraw from the Intermediate-Range Nuclear Forces (INF) Treaty with Russia underlines the current pace of strategic change. A nuclear order forged primarily during the days of the Cold War is on the wane.

Of course, the president’s statement is not, by itself, a valid mechanism for leaving the treaty. Rather, the US is obliged (under Article XV) to deliver a formal notification to Moscow of its intention to withdraw, citing the ‘extraordinary events’ that it believes justify such an action. Actual withdrawal would occur six months after the delivery of the notification.

Still, there’s no reason to imagine that Washington won’t follow through on its threat. So it’s not inappropriate to begin to contemplate a post-INF Treaty world. The breakdown of the treaty represents another serious blow to an ageing arms control architecture. Moreover, William Walker’s conception of nuclear order—a managed system of deterrence complemented by a managed system of abstinence—must surely take a heavy hit if the US and Russia walk away from a 30-year-old agreement to forsake an entire class of nuclear weapons.

Arms control critics say Trump’s going too far too fast: that the US has a range of options to respond to Russian violation of the INF Treaty without quitting the accord. That’s true. The treaty constrains only ground-launched ballistic and cruise missiles, so it’s certainly possible to devise a response that relies upon different delivery vehicles. (Indeed, part of the argument advanced in the 2018 US nuclear posture review in favour of the gradual reappearance of US sea-launched cruise missiles was to induce Moscow to return to INF Treaty compliance.)

But there’s a cost to doing that: top-level arms control can’t long survive—let alone thrive—on a diet of wilful blindness. Now’s as good a time as any to see where Moscow really wants to go. It might be we see a return to the days of greater Russian buy-in on key arms control agreements.

Was there ever such a time, readers might wonder? Yes, there was. Indeed, the archival materials suggest that the Soviet leadership, back in 1987, might well have been keener on an INF deal than its American counterpart. President Mikhail Gorbachev needed peace and stability in order to concentrate on his reform agenda at home. And none among the Moscow elite felt comfortable with the Pershing-2 deployments in Western Europe. The ground-launched cruise missiles certainly attracted their fair share of media and public attention, but it was the fast-flying Pershing ballistic missiles that most worried Moscow.

Perhaps it’s simply muddle-headed to expect a similar level of Russian enthusiasm for the INF Treaty today. The treaty constrains only two powers, the US and Russia, in a world where others are increasingly developing and deploying missiles within the treaty-defined ranges of 500 to 5,500 kilometres. These days, even North Korea has such a capability. China certainly does. So do India and Pakistan. And Israel and Iran. Saudi Arabia went down that path back in the 1980s. South Korea has a program in development. In short, across much of Eurasia—the continent upon which Russia lives—intermediate-range missiles are becoming much more common.

But in that case, why hasn’t Russia withdrawn from the INF Treaty? Certainly it has made its feelings known about the broader issue of ballistic-missile proliferation. If it genuinely sees such proliferation as an extraordinary event imperilling Russian national security interests, then it is perfectly at liberty to pull the plug and kill the treaty. Instead, Russia has chosen to cheat on the treaty and deny doing so—which means it hopes to pocket the gains from the arms control accord while simultaneously strengthening its own options.

Whatever Moscow’s motivations, the impending collapse of the INF Treaty suggests that we’re heading into an era of greater nuclear competition. New technologies are spawning new delivery systems, including hypersonic weapons, air-launched ballistic missiles, and huge, ocean-spanning torpedoes. It’s not just intermediate-range capabilities that are changing.

Moreover, the geopolitical climate is now markedly cooler; the level of political support among the great powers for a rebirth of the nuclear ordering project seems low. Structural factors bear some of the blame. It’s harder to define—and enshrine—strategic stability in a multipolar system than a bipolar one. Highly asymmetric relationships add another layer of complexity.

Today’s strategic pressures are more disintegrative than cohesive: and those pressures are just as likely to be felt in global nuclear relationships as in any other field of shared endeavour. Warnings of an impending nuclear arms race are probably too alarmist, but a more intense nuclear competition is definitely on the horizon. It looks like a bumpy ride ahead. Buckle up.