Quotes from book
Of Paradise and Power

Of Paradise and Power: America and Europe in the New World Order is an essay by Robert Kagan which attempts to explicate the differing approaches that the United States and the nations of Europe take towards the conduct of foreign policy. Kagan argues that the two have different philosophical outlooks on the use of power, which are the natural consequence of the United States' possession of power and the Europeans' lack of it.

“When you don't have a hammer, you don't want anything to look like a nail.”
Alternate version: If you don't have a hammer, you don't want anything to look like a nail.
Of Paradise and Power, p. 26
According to Kagan, this is a variation of the proverb "When you have a hammer, all problems start to look like nails." (p. 25 of the same book)