The US fought WW2 on two fronts and the Japan completely on their own (history check).

As for "we arguably won the Cold War", show me where the Soviet Union is on a map and tell me what's left to argue about.

As I was referring to the first Gulf War, is there really doubt about who won that one?

The point here is that you can make some argument about what constitutes "winning " a war, but comments such as "when did they actually win a war decisively?" and "The US has not and cannot win a war, period" are ridiculously and unequivocally false.