John Krasinski is Jack Ryan in Amazon series

Jack Ryan (John Krasinski) is a wolf who plays at being a sheep, observes an amused Frenchwoman in law enforcement.

Embodied by “Office” star Krasinski, the character starts as a geeky bicycle rider who could be a “Jeopardy!” champ. He grows believably from shrewd State Department analyst to challenged action hero in “Tom Clancy’s Jack Ryan,” an Amazon Prime series debuting Friday, Aug. 31.

The engrossing drama from Carlton Cuse (“Lost”) and Graham Roland (“Fringe”) reinvents Ryan, who has been played in the movies by Alec Baldwin, Ben Affleck, Chris Pine and most memorably Harrison Ford.

Krasinski is the main draw, because his nice-guy persona is stretched in fascinating ways. The actor’s appeal helps explain why the eight-episode series has been renewed for season two.

“For a guy who works behind a

desk you seem to like the field,” the Frenchwoman tells Ryan.

He is humane and resourceful on the job. Yet Ryan, whose body carries scars from his time as a Marine, detests evil and compromise.

He is thrust into dangers that test his mettle, and he is no superhero in action scenes staged with brutal force.

He clashes with James Greer (Wendell Pierce), an exacting boss hardened by experience and secrecy. “Wire” star Pierce lashes out with angry conviction.

Ryan slowly connects with Cathy Mueller (Abbie Cornish), a physician who’s smitten even though she’s warned he’s a selfrighteous Boy Scout. He isn’t, really, but he certainly knows how to leave a party.

“Jack Ryan” has the sleek look of an epic adventure as it jumps from Syria to Washington to Paris. The international acting styles don’t always mesh, but the series gives surprising depth to the villains, who have troubled pasts and unhappy relatives.

Increasingly riveting, the drama comes from a strong team. Morten Tyldum (“The Imitation Game”) directed the pilot. The executive producers include Michael Bay, Daniel Sackheim (“The Americans”) and Krasinski.

The actor, who scored as star and director of “A Quiet Place,” brings realistic savvy to Ryan. Bluster-free and no-nonsense, Krasinski presides over the series