It's the ideology

U.S. exceptionalism, in turn, requires not only a strong military force, but a military ideology that gives privilege to military adventurism and military personnel, and that assures limitless funding for such adventurism that is deeply engrained in machismo posture. The presence of the military ideology in advertising and sports means that military posturing is pervasive, so that the national anthem must be sung everywhere always, a kind of pervasiveness that shocks us when we see it performed in “lesser” societies of an authoritarian ilk. Thus military exhibits of flags, anthems, marching, and saluting of the kind that endorsed National Socialism in Germany become commonplace among us—America and Its Guns: A Theological Expose, page xii

<idle musing>
I'll bet you don't even notice it, do you? It's so commonplace that it's like the fish who doesn't know it's wet. Flags everywhere—especially since 9/11/2001.
</idle musing>