If so, he will find a willing partner in Putin. A yearning for a return to the grand alliance has been a persistent theme of Russian foreign policy. After 9/11, Putin offered such an alliance to George W. Bush, but was spurned in favor of American unilateralism in Iraq and Afghanistan. Under Barack Obama, the so-called reset in U.S.-Russian relations promised a return to collaboration, but such hopes were dashed by Western military intervention in Libya in 2011 and by Russia’s unilateral response to the Ukrainian civil war in 2014.

A new grand alliance may seem like a utopian dream. But history shows that cooperation between the world’s two great nuclear powers is both possible and necessary. Franklin Roosevelt collaborated with Stalin to defeat Hitler. Eisenhower worked to defuse the tensions of the Cold War after Stalin’s death in 1953. Brezhnev and Nixon created the détente of the 1970s. Reagan abandoned his hardline anti-Soviet policies and embraced Gorbachev’s glasnost revolution in the U.S.S.R.

Trump did not betray America in Helsinki; he opened a dialogue with Putin that could and should lead to fruitful and potentially far-reaching collaboration between the U.S. and Russia.