US economic advantages, last 100 years

Inspired by Canada’s attempt to integrate into the European Union, here is a non-exhaustive (and highly correlated) list of advantages that Americans have benefited from, been subsidized by, or captured rents from over the last 100 years:

Immigration
The world’s largest free trade zone (50 states, 3.8 million square miles, 116m-350m people)
Friendly neighbors
Two coasts to transport goods from
Serving as the world’s reserve currency
The lowest perceived probability of defaulting on it’s national debt
The absence of historic or prospective hyperinflation
Possessing nuclear weapons that can both credibly be used and, more importantly, not used (NB: I’m not excited about this one, but I at least can’t rule out that it has deterred antagonistic military action)
The world’s most prestigious higher education institutions
Relatively high levels of interpersonal trust

I have no doubt that there is many, many more. I just wonder which of these we will still be intact in 10 years. Are they all still intact now?

Addendum: This is not meant to be a list of simply good policy choices. Those are, in actuality, far easier to achieve. Rather, this is a list of phystical and societal attributes that either simply have to exist or take a significant amount of coordination across time and, more difficult still, generations, to achieve.