This movie had been sitting around on my coffee table for weeks, and I finally decided to watch it. It is based on a book of the same, by John Le Carre.
Pierce Brosnan plays Andrew Osnard, a disgraced MI-6 agent, sent to Panama as punishment for having an affair with an ambassador's mistress on his previous assignment. His job in Panama is to learn what the President intends to do with the Canal: keep it and operate it, sell it to another country, etc. He befriends Harry Pendel, a tailor played by Geoffrey Rush, partly because Mr. Pendel knows various wealthy people in the capital (he is a high-end tailor) and his wife Louisa, played by Jamie Lee Curtis, works for the President.
This spy doesn't operate like James Bond; instead most of the spycraft is finding a weakness and exploiting it. Osnard finds out Pendel owes some money to a bank, so he dangles wads of cash in front of him, in exchange for introductions and information. Pendel is eager to please, so he exaggerates the role of friends of his, who in the past were active in opposing the Noriega government but have since mellowed, to concoct an anti-government movement. Osnard in turn embellishes this info to his bosses because he knows what they want to hear. He presses Pendel for more info and the cycle continues.
By the end, the British and Americans are convinced enough to fund weapons for the fake opposition group, and stage a near-invasion of Panama! In many ways the movie is very cynical about how intelligence and foreign policy decisions are made.
In the confusion at the end, we find out Osnard's real motive for everything: revenge on MI-6 for exiling him as punishment. His superiors deliver money to fund the opposition group, but Osnard steals it. After paying a bribe that allows him on a departing flight, he makes off with the cash! On the flight he meets Francesca, an embassy worker played by Catherine McCormack, who he had an affair with. I'm not sure how much of it she was in on, if any, or if them being on the flight was a coincidence or not. Maybe the book is clearer.