John Krasinski returns as Jack Ryan in the Amazon Prime Video series “Tom Clancy’s Jack Ryan,” three years since we last saw him in the role. Krasinski says he had to work hard to get back into “Jack Ryan-shape” for filming, especially after being sequestered at home for many months during the pandemic. He was motivated to get fit by the knowledge that the show was providing work for so many whose livelihood depended on it. In the new episodes, Ryan discovers an underground plot by Russia to invade surrounding countries and reestablish the Soviet empire. The storyline may sound familiar but production wrapped long before Russia invaded Ukraine. The new season starts streaming Wednesday.