A military alliance of the U.S., Canada and many European countries that promise to defend each other.
NATO's members promise that an attack on one is an attack on all. Founded in 1949 with 12 countries, it now has over 30, and Americans debate how much the U.S. should spend on it compared with its allies.
"The country asked to join NATO after its neighbour was invaded."
Filed under the world in the glossary, with every word used on How I Lean.
Nine questions, about three minutes, and you'll see where you lean.