It may be the highest-stakes move for Donald Trump in his entire presidency — unilaterally removing the United States from yet another international treaty, this time with immediate and potentially existential consequences.

Trump's Oct. 20 announcement that Washington would withdraw from the Intermediate-Range Nuclear Forces Treaty (INF) with Russia, a landmark 1987 agreement signed by U.S. President Ronald Reagan and Soviet leader Mikhail Gorbachev to remove nuclear weapons from Europe, eliminates whatever curbs may be left on the development and deployment of a whole new generation of lethal and more readily deployable nuclear arms. Gone will be any restraints on Russian President Vladimir Putin from modernizing and updating his nuclear arsenal, thereby reviving the nuclear arms race at a time when a new round of nuclear forces in North Korea and Iran threaten the world and new missile technologies are proliferating.

Trump's ill-conceived and poorly thought-out action plays directly into Putin's hands. As much as the Russian leader may already be flouting the principles and provisions of that treaty, he can now do so with impunity and none of the consequences of being labeled the transgressor.