It's not easy replacing Harrison Ford as a beloved screen hero, but Ben Affleck brings fresh vitality to The Sum of All Fears , reviving Paramount's Tom Clancy franchise in the role Ford made famous. As CIA agent Jack Ryan, Affleck is a rookie in the covert ranks, unraveling a plot that lures Russian and American superpowers into a nuclear standoff, while a neofascist faction turns most of Baltimore into an atomic wasteland and holds the world in the grip of a terrorist nightmare. Affleck combines sharp intelligence with a new-guy's perspective, while a senior agent (Morgan Freeman) passes the torch of back-channel authority. The result is one of the best Clancy films to date, ably helmed by Phil Alden Robinson (whose comic thriller Sneakers was sorely underrated) with a stellar supporting cast, and adapted with abundant humor, humanity, and thrills by Donnie Brasco screenwriter Paul Attanasio and cowriter Daniel Pyne. Even the typically reticent Clancy would approve. --Jeff Shannon