Why American veterans are dropping everything to train Ukrainians

What moves people from passive sympathy to active participation? American military veterans who got off their couches to help in this war cite Ukrainian resolve and the conflict’s moral clarity.

The former U.S. Army combat medic watched the war unfold from the safety of his Maryland home, his admiration growing for Ukrainians’ courage in the face of an overwhelming Russian invasion force.

For him, previous foreign conflicts had been no more than news headlines: Russia’s annexation of Ukraine’s Crimean Peninsula in 2014, for example, or Moscow’s role propping up the...