The Man Who Knew Too Little (1997) on Netflix

Wallace Ritchie, an American vacationer in London, doesn't know that the bullets are real and the truth serum true. He thinks the intrigue erupting around him is part of an audience-participation theater event. Yet the world's fate depends on this gullible goofus who can't even spell CIA. Ritchie is the naive spy who comes in very bold. The deadpan Ritchie blissfully treads into a dead-serious realm. He can't believe how believable the make-believe seems. But as Ritchie's cloak-and-dagger experiences with agents, a femme fatale, a corpse, highway pursuits (lesson #1: drive on the left), assassins and a ticking time bomb amply prove, variety isn't just the spice of live. It's the life of spies.