European countries are growing concerned that Russia may decide to strike beyond the borders of Ukraine, leading governments across the continent to warn that any attempt by Moscow to destabilize the region will backfire.

Earlier this week, Denmark accused a Russian warship of firing two emergency flares at a Danish military helicopter over the Baltic Sea. Moscow claimed the flares were fired to prevent a “provocation.” Russia is also believed to have been responsible for launching a drone that was shot down by NATO fighter jets over Lithuanian airspace this week. Moscow has not taken responsibility for the drone or otherwise commented on the incident.