Why does the old standard, "The Mouse that Roared" come to mind.
That's where a tiny country declares "War" on the U.S., and then reaps millions in foreign aid to rebuild, I think. Used to be a regular in the class plys in High Schools across the country, along with "Arsenic and Old Lace".
The book was by Leonard Wibberly:
http://en.wikipedia.org/wiki/Leonard_Wibberley
The idea was that the Duchy of Grand Fenwick would declare war on the US, lose, and get rehabilitated with millions of dollars.
Unfortunately, the invasion force of about 30 men-at-arms equipped with longbows and swords, accidentally captures a professor and the Q-Bomb (which can blow up North America). So Grand Fenwick accidentally wins the war and becomes the most powerful country on Earth...
That's the story...The Mouse That Roared.
Why it was brought to mind was that you could buy this island, join the UN, declare war on the U.S., then get funding via Foreign Aid (the extortion scheme used by all the third world banana republics today to get millions of U.S. dollars NOT to cause trouble!)