Andrey, 21, had never held a gun before this week. It came as a shock when he received a phone call telling him he had been called up for military duty.

Two days later, he was sitting on a bus on his way to join an artillery unit of the Donetsk People¡¯s Republic, one of two breakaway territories in eastern Ukraine that Russian President Vladimir Putin formally recognized on Monday and brought under Moscow¡¯s protection.

In preparation for the possibility of all-out war, the separatists have been telling men age 18 to 55 to take up arms, and even some older men have joined up. Andrey, who enlisted with a student friend, said they had no choice in the matter.