The Duchy of Grand Fenwick decides that the only way to get out of their economic woes is to declare war on the United States, lose and accept foreign aid. They send an invasion force (in chain mail, armed with bows and arrows) to New York and they arrive during a nuclear drill that has cleared the streets.
"The Mouse That Roared" — movie produced in UK and released in 1959. It has a good rating on IMDb: 6.9 stars out of 10. It is a feature-length film with a runtime of 1h 23min. "The Mouse That Roared" is currently available for rent and to buy on Apple TV and Amazon Store. Click on a playlink to watch it now!