the answer is NO
USA in its current form would not even exist but for the Manifest Destiny policy - i.e. it is our destiny to wipe out an entire race of people. Not too different from Nazi theory about the Jews.
I suppose it is inevitable that the power of being No. 1 goes to your head and brings on daft expansionist policies. As you rightly point out Britain went mad with power lust in the late 19th century. The country that supposedly brought civilisation to most of the world turned out to be the first country to use concentration camps, during the Boer War. No exceptions for women & children.
Does this mean that we Brits should be proud of this passage in our history? Well I for one am ashamed of this kind of stuff.
One thing we can be proud of is that just about every country we once controlled and now don't - USA, Aussie, India, Canada, Eire, much of Africa, Hong Kong - now get along pretty well with us. For the most part we managed to hand them back to their true owners with a bit of style and class, though in the case of Ireland I can't really say we did this.
I hope I live to be able to say the same about the USA. Vietnam was a bungle, Afghanistan is not clever and Iraq is shaping up to be worse than either of those adventures. Current US foeign policy appears to desire to create as many martyrs and revenge-thirsting folk as possible.