The concepts of a "superpower" and "the world's mightiest power" are ideas that easily go to the heads of people who wish to use that power. Even if they mean well it can be difficult to see clearly the ends and means, and given the interests of power blocs in government, industry and capital meaning well may not always be the case.
The problem with great power is how to apply it. We've had nuclear weapons for well over half a century, but in wars like Viet Nam and the current problems with terrorism these weapons are inapplicable. Even against the USSR they were only valid as threats, their use would have been irredeemable disaster. Economic pressures, moral pressure, blockade, international cooperation and use of international credit to control the behavior of states are better weapons than the military in most cases. The vagaries of chance in warfare are too unknowable; almost any other approach is preferable.
Unfortunately, the victory of World War II to some degree blinded the American government and military to the use of these other strategic means. Impatience and a belief that our power is overwhelming has led to an overrealiance on the military. The most competent use of our military since WW II was the Clinton administration's handling of the Balkan crises in the 1990s. The political leadership assessed the situation, and essentially told the military "This is what we want to accomplish, this is how much of the money, materiel and lives of Americans we are willing to pay, can it be done?" The military made a plan and carried it out in a situation that could easily have led to a third world war.
But the real problem is that not only the leaders but much of the population of the US has fallen into the trap of believing that our military supremacy in the past must extend into the future. The world is far different now.
Most Americans believe we have the capability to surmount any odds, and that's good. But we need to keep a closer watch on our leaders, and that is a lesson we have learned over the past eight years. We have alienated the rest of the world by continuing our policy of being "the World's Policeman," a role the world did need us for during the Cold War but requires no longer. We have to see that we are one of the world's countries, not necessarily the most important. We can help other countries, but then again they might not need the kind of help we think, or they might not want our help at all.
I certainly hope that President Obama's administration will reassure the world that we have their best interests at heart, not only those of our largest corporations. Exposing the abuses of American power is one thing that must be done to show the world we are not descending to the level of the Nazis. Focusing on the real threats to our security is another, instead of targeting situations a few major corporations can make a fortune on. Repairing our economy will repair the world's economy, since the world's economy basically is driven by ours. Leading the way into a greener future by pouring manpower and research into new technologies is yet another. Perhaps most importantly, we have to do something about the debt crisis hanging over the heads of every nation on earth, with all governments owing enormous sums of money. Most of the debts have been accumulated in ways which only benefited the ruling elites, and the regular citizens are the ones who must suffer through the shortages and price raises caused by the situation.