[Modernman]

That is, for the benefit of WHOM?

For our own benefit. And for the benefit of our various allies around the world.

We can withdraw from the world and hope for the best. The effects will be even worse than in the 1930's and 1940's. China will fill the gap and dominate the Western Pacific. Islamic fundamentalism will continue to spread. Nuclear war between India and Pakistan will become even more likely.

In the long-run, though, isolationism is just wishful thinking.

[A. Pole]

We can withdraw from the world and hope for the best. The effects will be even worse than in the 1930's and 1940's.

One should not be arrogant about being supreme and "indispensable nation". The pride comes before the fall.