“They seem to be some kind of provocation to test how we would react,” said a security agency official, who asked not to be identified because of the delicacy of the issue. He said there were no signs of separatist fervor in Latgale itself and described the Latgalian People’s Republic as an “artificial creation by outsiders.”

Eastern Ukraine also displayed no separatist fervor until Russian-backed gunmen in March 2014 seized government buildings in Donetsk, silenced local supporters of Ukraine’s central government and, aided by Russian state television, mobilized a previously passive population to the separatist cause.

“The crux of the matter is that you have to be in charge, in control. Once you give the initiative to the other side, you are lost,” said Janis Sarts, the state secretary for Latvia’s Defense Ministry. He noted that regular rotations of NATO troops and aircraft through Latvia had sent a firm message to Moscow that “the risks would be tremendous” if it tried to copy its Ukrainian playbook in the Baltics.

In a blunt, if theatrical, warning to any would-be troublemakers, Latvian soldiers, border troops and the local police held a joint exercise last month here in Rezekne, the Latgale region’s historical and cultural capital.

With shouts of “hands in the air” as a military helicopter clattered overhead, a special forces unit of Latvia’s border troops stormed the district council building to confront mock “terrorists” who had seized the premises.

The raid lasted just a few minutes and ended with the rabble being dragged from the building and then dumped into a military truck.