Writing for the UK’s The Independent, Johann Mari has an excellent article on the historical differences between European and American foriegn policies:

The commitment to supranationalism is so strong that the EU is seen as just one such body: the United Nations is another institutional layer that should facilitate dialogue and prevent war. Therefore, as Kagan explains, Europe “is moving beyond power into a self-contained world of laws and rules and transnational negotiation and co-operation”. The European vision, he notes with a revealing sneer, of “a post-historical paradise of peace and relative prosperity, is the realisation of Kant’s ‘Perpetual Peace’.” Kagan should also have pointed out that the key European value is to prevent war, at almost any cost.

In the US, the lesson drawn from the 20th century, and indeed before then, is very different. They believe that confronting “evil” (a word used without embarrassment), even at the risk of war, pays off in the end. It is only through the threat of violence that peace and freedom can ultimately prevail. The American public overwhelmingly understands their historical narrative as one of the nation fighting bravely against evil, time and again: the British empire of George III, the Third Reich, the Soviet Union and now Islamofascism. Sometimes, they admit, this has led them into mistakes, like Vietnam, but these were mistakes made in a noble cause. The key American value (in their own self-understanding, although often not in practice) is to prevent not war but tyranny – and, crucially, threats to US security.