Null says, "I'm mocking tribalist flag-wavers...like you."
And, there begins the friction. Why mock them? What harm do they do to you?
You might as well mock any Yankees zealot, classical music lover, or what-have-you fan ...
This soldier, whether he knows it or not, is defending a Constitution which has revolutionized the world and has encouraged freedom and democracy in its international conduct; however much capitalistic, economic hegemony that also inculcates in the exercise of their liberty.
Certainly all of Americas old enemies have benefitted in that freedom and economic elevation; much less the friends who have joined in helping spread political and economic freedom around the worlk.
I'd venture to guess that without America's influence, using economics as a peaceful 'weapon', Great Britain would still rule their imperialistic domain(s), as well as France and the other paleo-imperialists which our Consitution has confounded into agreement with it; if not adopted as their national yoke on government.
All soldiers fight for that: Constitution, our president as commander in chief, our nation - down to and including the 'tribal' town, family and friends.
Your high horse sneer is a petty subversion of that document and that American hope for world wide freedom and liberty, at best ...