In a few days the nuclear risks associated with Russia’s invasion of Ukraine have gone from the background to front and center. Over the weekend, Russian president Vladimir Putin declared that nuclear forces were being placed on “special combat readiness.” Precisely what Putin’s declaration means for the disposition of Russian nuclear forces is unclear, but the declaration was the clearest example of nuclear signaling thus far in the crisis.

Putin’s statement comes amid a rapid escalation of economic and diplomatic actions to punish him and Russia for attacking Ukraine. The breakneck speed and sweeping scope of Russia’s economic and diplomatic isolation are unprecedented. This isolation combined with Russia’s poor showing on the battlefield put Putin in an increasingly desperate situation.

The nuclear announcement is likely intended as a warning against further and more direct intervention by the United States and Europe, especially military intervention. Put differently, Russia’s message appears to be that costs inflicted on it by the West could increase nuclear danger, so don’t think that more pressure—and especially direct military intervention—are going to be cost free.

There are several options for the U.S. and its allies to respond to Putin’s signal in ways that reduce nuclear risk. The first step, which Washington has already taken, is to signal restraint by not elevating the alert level of the U.S. nuclear arsenal. Another action to avoid is making explicit threats of regime change against Russia, which will only heighten Putin’s perceptions of existential danger. Finally, Putin’s announcement is a stark reminder that this is a nuclear crisis. Biden’s position that the U.S. would not intervene with military force should continue to be U.S. policy.

Regarding the pressure campaign against Russia, the best thing for the U.S. and its allies to do is to clearly message what things Russia would need to do to reduce the pressure. The price can be set high, such as lifting some sanctions in exchange for a complete Russian military withdrawal from Ukraine. Even if Putin is unlikely to take the path out, having a road for him to deescalate the conflict is important. If the pain will persist no matter Russia’s course of action, then there is little incentive for Putin to not escalate further.