Dublin taxi driver joke

Brian Cowen, the Irish taoiseach (prime minister) calls up Barack Obama to declare war.

"Fine," says Obama.
"Hang on," says Cowen, "how many aircraft carriers do you have?"
"About fifty," says Obama.
"Jaysis. Listen, I'll call you back in an hour."

An hour later ...
Cowen: "The war's still on. But hang on, how many fighter jets do you have?"
Obama: "Um, maybe three hundred."
Cowen: "Oh. Hang on, I'll call you back in an hour."

An hour later:
Obama: "So are you phoning to call off the war?"
Cowen: "Not at all, not at all. The war's still on. But hang on - how many soldiers do you have?"
Obama thinks a bit. "I believe about 600,000."
Silence.
Cowen: "War's off. We've nowhere to put the prisoners."