The United States pulled Europe’s fat out of the fire (and their head out of their collective arse) 3 times in the 20st Century (WWI, WWII, and the Cold War).
A point the author makes in his article.
America has enormous debts but it still spends as much money on defence as all the rest of the world put together.
And if that makes you uncomfortable, it is worth remembering that wherever you are, there is a good chance that if your country is ever invaded, your leader's first phone call will be to the White House in Washington.