Call of Duty

Like 10,000 other military veterans, Jim Reynolds transitioned into education via the federal Troops to Teachers program. But does the 40-year-old National Guard sergeant have what it takes?

Semper Gumby .

That’s the catchphrase Sergeant James Reynolds and his Army National Guard unit—part of the 28th Infantry Division—lived by while serving as peacekeepers in Bosnia, back in 2002-03. Semper Fidelis , the borrowed Marine Corps motto, is Latin for “Always Faithful.” Cross it with the iconically flexible green Claymation character, and you have a slogan that helps keep you—and others—out of harm’s way.

Reynolds learned as much early in his deployment, while serving as rear gunner on a Humvee patrolling a Bosnian town. Although the streets were considered safe, the four-man unit, he recalls, was gung-ho—“prepared for anything.” Reynolds was facing backward, watching houses stream past. “All of a sudden, in a break in a wall, a little boy steps out with a gun and points it at me,” he says. “Now, I’m really keyed up because we’re fresh in-country. So I swing over. But because it’s a little kid—he must have been, like, 8—I hesitated.” The gun, it turns...