The US also has the best natural barriers to invasion in the world. The only access points are through the Arctic (good luck with that), or by traveling over a damn ocean to assault beaches on North American soil. When not only America has the largest navy in the world, but several of the runner ups are close allies, how do you plan on even getting to the US with your forces? You don’t.

As you say, the US is well positioned in this changing world. It’s one of the few countries almost guaranteed to continue to do well.