In discussing NATO below, I failed to mention the special case of NATO member Canada. Like Europe, Canada pretty much lets the U.S. defend it.
Canada knows we cannot let a hostile power take Canada as that would give an enemy a 3000 mile border with us, one we've never prepared to defend. So Canada can be lackadaisical about defense and spend their tax dollars on "free" social programs, as the Europeans do.
I wonder if our northern neighbors have sussed out that if we ever are forced to defend Canada - move large military units north to confront an invader - their sovereignty will be endangered. Those military units may morph into an army of occupation.
