The Mouse That Roared (1959)

When the tiny nation of Grand Fenwick's only export, a special wine, begins to be produced in California, their entire economy collapses. Things look dire until Prime Minister Rupert Mountjoy (Peter Sellers) points out that no country that has declared war on the United States has ever gone hungry. When Field Marshall Tully Bascombe (Peter Sellers) and the 23 other men in the Grand Fenwick army invade the United States, their plan to immediately surrender unravels.