Briton Tony Scott (“Top Gun,” “Spy Game,” “Man on Fire”) too often surrenders his curiosity about social paranoia to violence and special effects. Not here. It’s the mid-1990s, a time of deep instability in post-Soviet Russia. Fearing civil war, the U.S. nuclear attack sub “Alabama” is deployed, with old school Captain Frank Ramsey (Gene Hackman) in command. His No. 2 is silky Lt. Commander Ron Hunter (Denzel Washington). Ramsey is a shoot-first Cold Warrior, Hunter deliberate and rational. This is good submarine picture in the tradition of “Das Boot” and “Run Silent, Run Deep.” Scott coaxes credible loathing between Hackman and Washington, adversarial archetypes in the hemmed-in depths. Viggo Mortensen and James Gandolfini bulk up an able cast.