United States Invasion of Panama By mfeldmanyalu Nov 1, 1987 U.S. Ends Military and Financial Aid to Panama Period: Nov 1, 1987 to Jan 31, 1990 U.S. Invasion of Panama May 1, 1989 Noriega voids election results, causing tensions to build Dec 15, 1989 Noriega declares war with the U.S. and pronounces himself leader of Panama Dec 20, 1989 U.S. Invasion of Panama Begins Jan 1, 1990 Manuel Noriega surrenders, Operation Just Cause Ends