First and most urgently, President Biden should publicly call upon the Russian military not to obey orders to use nuclear weapons against Ukraine or NATO. Vladimir Putin may have nothing to lose, but the Russian people have everything to live for. Private military to military channels should reinforce that message.

Second, American missile defenses in Europe should be placed on higher levels of readiness. Small numbers of short and medium range ballistic missiles are the most likely Russian nuclear delivery systems, but these are vulnerable to AEGIS Ashore ballistic missile defense systems in Romania and in Poland. The former has been operating for five years. The latter was scheduled to be operational by the end of 2022. This should be accelerated.

The radars of those systems were deliberately not optimized for defense against Russian missiles. But this can be ameliorated by linking those systems to radars elsewhere.

The United States also has four ships with AEGIS systems that are dedicated to NATO missile defense based in Spain. They should be sent to the Baltic or the Black Sea—or wherever they will be most useful.