In The Mouse that Roared, the rivalry of the Cold War is systematically parodied.
The leaders of the small European Duchy of Grand Fenwick declare war on the USA when their country is plunged to the verge of bankruptcy when an American company starts producing an imitation of their only export, a discerning wine.
In an attempt to get the goods and money that – the prime minister Count Mountjoy (Peter Sellers) points out – America pours on its defeated enemies they must declare war, and then rely upon the United States for economic assistance.
War having been declared on the United States, the small army led by Tully Bascombe (Sellers in multiple roles) in its medieval chain mail and armed with longbows crosses the Atlantic.
Unknowingly, they arrive in a New York that is deserted because of a national air raid drill in connection with work on a new and powerful bomb.
The medieval army is thus unopposed and by accident manages to capture the Q-Bomb, along with its inventor Professor Kokintz (David Kossoff) and his daughter Helen (Jean Seberg), and then take them back to Grand Fenwick.
The US wants the return of the Q-Bomb, so decides to send an ambassador to the small country and forge a peace deal.
Thus, the small state both ‘defeats’ the prime modern state and seizes the main symbol of the Cold War. Inevitably though, in the dungeons of Grand Fenwick, the bomb is found to be a dud.
Tully Bascombe/Grand Duchess Gloriana XII/Prime Minister Count Mountjoy