The British empire had a British, not a universal, purpose, although naturally its propagandists also found more altruistic motives. So the abolition of the slave trade was used to justify British naval power, as human rights today are often used to justify US military power. On the other hand the US, like revolutionary France and revolutionary Russia, is a great power based on a universalist revolution - and therefore on the belief that the rest of the world should follow its example, or even that it should help liberate the rest of the world. Few things are more dangerous than empires pursuing their own interest in the belief that they are doing humanity a favour.

The cold war turned the US into the hegemon of the western world. However, this was as the head of an alliance. In a way, Europe then recognised the logic of a US world empire, whereas today the US government is reacting to the fact that the US empire and its goals are no longer genuinely accepted. In fact the present US policy is more unpopular than the policy of any other US government has ever been, and probably than that of any other great power has ever been.

marxist historian eric hobsbawm on america's imperial delusion