Michael Ferkol, who once served as a supply specialist with engineer battalions in the U.S. Army, had been in Rome studying archaeology when he heard the Ukrainian president¡¯s appeal for foreign fighters.

Within days, Ferkol said, he presented himself at a military recruiting office in the western Ukrainian city of Lviv, hoping to be taken on as a front-line paramedic.

¡°I told them I wanted to triage patients,¡± said the 29-year-old, who has no combat experience. ¡°There was a Finnish guy there too, and he was like, ¡®I just want to kill Russians.¡¯¡±