Mutually assured destruction inches closer to reality as North Korea, Russia and the West expand their nuclear deterrents.

(Originally published Oct. 27 in “What in the World“) Russian President Vladimir Putin took time out of his busy schedule bombarding Ukraine to watch his military conduct regular nuclear launch drills. It’s always nice when the boss demonstrates an interest.

The tests may have been regular, but Putin’s repeated references recently to the potential use of nuclear weapons—accusing Ukraine of planning to deploy a “dirty bomb” and warning that Russia is prepared to deploy nuclear weapons in Ukraine if necessary—are raising concerns in Washington about a heightened risk of nuclear conflict in Europe.

The U.S. is responding by accelerating its upgrade of nuclear bombs at U.S. and North Atlantic Treaty Organization bases in Europe. Washington has long been planning to deploy the B61-12 air-dropped gravity bomb but is now moving the bomb’s deployment up to December. While the move is designed to boost the preparedness of Western forces for nuclear conflict, it will undoubtedly be criticized in Moscow as a further provocation by NATO.

Putin has already decided, argues former CIA Deputy Assistant Director for Europe and Eurasia Peter Clement in Foreign Affairs, that he must respond to Ukrainian gains in the war by raising the stakes, rather than negotiating. With public support dwindling at home, he has already called up more draftees, and could further expand his moves to deprive Europe of energy during the winter. He could launch a wave of cyberattacks against Western infrastructure. Finally, he could deploy chemical or nuclear weapons against Ukraine.

Japan, South Korea and the United States, meanwhile, warned North Korea that they would respond “decisively” if Pyongyang goes through with plans to conduct a nuclear test of its own.