This conversation starts with commentary on patriotic-themed football uniforms and ends with the Star Spangled Banner being called "a war anthem. " True, it was born in war and describes a battle. But the name "war anthem" suggests it's a battle cry or call to war. In that regard it falls short. It is, really, a freedom anthem; celebrating that the banner continued to fly over the land of the free; America was still the land of the free and the home of the brave because the flag was still there.
As for singing it at the start of sporting events; opposition to this has cut across ideological lines. Some consider it politicizing a sporting event, which I think is nonsense, unless you have political opposition to honoring your country. Some go the other way, and see it as cheapening the Anthem.
I have always seen it this way; in a few minutes, on the field of play, two opponents will meet and compete, fiercely. But before then, we all stand, honor our country and recognize that whether our team wins or loses, we're all Americans.