We can destroy the planet several times over, all out war againts us is unwinable. The most anyone can hope for is to become a threat to our security, and no rational person wants that.
War isn't about a fair fight, it's about defense, imposing your will on others, and killing the enemy. We have the right to go to war against anyone we choose(which is usually because we deem them a threat to us or our intrests), just like any other sovereign nation.
The chinese have said something to the effect that war with us is inevitable, the thing is how do you attack you best customer? We pump billions into china. I sure there's an equvilent chinese proverb about not biting the hand that feeds you. And unless you plan on killing us all there's no way you'd pacify us.
I belive that we are possibly the most tollerant nation on earth. But then I have a low opinion of the rest of the world so maybe we aren't angels but we are better than most and certanly better than any nation in history with anywhere near as much power(relatively, since no one's ever been this powerful) as we have.