The Mouse that Roared by Leonard Wibberley (1955)Read about the other entries on the list.
The tiny principality of Grand Fenwick had no intention of blackmailing the world with atomic doom. Faced with economic calamity (Americans had successfully copied Grand Fenwick’s principal export, Pinot Grand Fenwick wine), they came up with a simple but brilliant plan: declare war on the United States of America, lose, capitulate, and then wait for US to expend billions of dollars rebuilding Grand Fenwick (shades of the Marshall Plan). Since Grand Fenwick had not upgraded its military toolkit since the Hundred Years War, there was no way this cunning scheme could go wrong. Or so it seemed.
The handful of men-at-arms dispatched to New York City find a city abandoned thanks to a Cold War-era Civil Defense exercise. Hunting for someone to whom they might surrender, they stumble across Dr. Kokintz and his Q-bomb demonstration model. Both Kokintz and his device are carried off to Grand Fenwick, whereupon the astounded Grand Fenwickians discover to their alarm that they are now in possession of a weapon that could, if detonated, depopulate a continent. Still, having the eyes of the world on them has possibilities…provided nobody jostles the delicate Q-bomb.
--Marshal Zeringue