The moment that persuaded Adam Driver to pursue an acting career didn’t come when he was cast as the Leading Player in a college production of “Pippin,” or even when he was accepted to Juilliard. It happened one thankfully windy afternoon as a cloud of deadly white phosphorus  a high-powered chemical that can burn through cars  inched its way toward him and a group of fellow Marines during a mishap in a California training exercise.

“They fired on us as opposed to the target,” said Mr. Driver, who joined the military at 18, a few months after 9/11. “That was the first time in training anything life or death had ever happened. We all ran. If it wasn’t windy that day we would have been dead.”

He laughed before continuing: “I made up my mind then that I wanted to smoke cigarettes and pursue acting. When you get out of the Marine Corps you think you can do anything.” He stuck to his plan (minus the cigarettes).