How to punish wartime collaborators? Ukraine charts painful course

KYIV, Ukraine — The stories of betrayal trickle out weekly or even daily: A villager tips off an occupying Russian military unit about identities and activities of volunteer defenders. A resident of a besieged city clandestinely calls in the coordinates of a Ukrainian troop encampment. A small-town mayor tells neighbors that encroaching Russian troops mean no harm.

For as long as humans have waged war, they have feared the enemy within. Collaboration and treason run like dark threads through the tapestry of nearly every wartime narrative, no matter how triumphal: in ancient Greece, in Revolutionary-era America, in Nazi-occupied France.

And in Ukraine, which is fighting an existential battle to defend itself from Vladimir Putin's armies.

Those who study the phenomenon of collaboration say a choice to betray one's country and compatriots can be motivated by a host of factors: divided loyalties, personal