[mogrim]

Alternatively, NATO provides legal and moral support to the centuries old concept of buffer states - the US provides military support to stop the spread of communism, which is left unchecked would have reached the US isolated in a hostile world.

As a European (with a keen interest in history) I'm not ungrateful for US aid, but to suggest that aid was entirely selfless is incorrect. (You may wish to draw parallels with the French support that made the American revolution a success, a similar situation...)