Stop worrying about the growth of others and focus on our own growth. This is natural without a 1945 or 1991 event:
In relative terms, there is a reasonable probability that the United States is likely to remain more powerful than any single state in the coming decades. We do not live in a “post-American world,” but neither do we live any longer in the “American era” of the late 20th century. In terms of primacy, the United States will be “first” but not “sole.” No one has a crystal ball, but the National Intelligence Council (which I once chaired) may be correct in its 2012 projection that although the unipolar moment is over, the United States probably will remain first among equals among the other great powers in 2030 because of the multifaceted nature of its power and legacies of its leadership.
I tossed off my own estimate of 2040 five years ago:
For fun, let me toss off a scenario of the future from our point of view off the top of my head with absolutely no research whatsoever to support it.
It is a recurring theme in our country to predict our imminent fall from dominance. Fascism, Soviet Communism, democratic Socialism, Japanese planned economy, European socialism (again), and now China are projected as supplanting America as the dominant power. Yet we keep adapting. The United States remains the dominant economic and military power on the planet.
I think this will remain even though our portion of the global pie will decline as China and India continue to grow. And as we near mid-century, we will remain the dominant power and--lacking nearby foes that compel us to devote major resources to homeland defense--will have the most free power to help allies and oppose enemies.
I then went on a tour of the world's regions. But I don't have foot notes, or anything.