Enigma (1983)

Before he was president, Martin Sheen was a communist defector in Enigma (1983). He's recruited by U.S. intelligence to return to East Germany to thwart an assassination attempt by political dissidents. Things really heat up in Red Square when Sheen employs his ex-girlfriend Brigitte Fossey to seduce the Russian spy in charge of the enigma, basically a super-sophisticated secret-decoder ring. There's a snag in his plan: Brigitte falls for the Russian Bear, played by Sam Neill. The thriller/love triangle gets hairy when Brigitte flashes her love triangle--plus some spherical sacks and her rectangular rump. Some of the ins-and-outs of the complex plot remain an enigma, but Brigitte's exposure heats up the Cold War in your pants.