During the surge in Iraq in 2008, Nathan Witmer led an Army scout platoon in a thicket of villages rife with insurgents and roadside bombs. What he really wants to do is direct.

Or maybe write — or produce.

“Anything with movies was always the dream,” said Mr. Witmer, who left active duty in 2010.

Like many troops leaving the military, he was steered instead toward jobs in government agencies that offered preferential hiring or with big corporations that recruited veterans, and he assumed his hope of working in show business would remain only that.

But after selling medical equipment for two years, he had the chance to join a five-week industry boot camp designed to bring young veterans into the television business. To his surprise, it was run by one of the Iraq war’s fiercest critics, Jon Stewart, the longtime host of Comedy Central’s “The Daily Show.”