Largely, we've not been defending ourselves, but rather, maintaining our interests and investments. Who wants to stand behind that other than the misinformed?
There are still those that believe they're fulfilling some patriotic duty, but that only feeds back into my original statement. The "bad apples" only serve to highlight part of the problem. Culling and replanting the "orchard" is a magnitude of order more difficult.
I will stand behind US Military maintenance to the degree that NATO remains the top world power, but I will also stand behind any global demilitarization such as the many past treaties to dismantle nuclear weapons. It's okay for nuance to exist.