The British anthem isn't originally a national anthem at all, and there weren't any when it was written - it was called "The King's Anthem" for its first century or so. (It has also never had any standard text, so getting aerated about the anti-Scottish verse from the 18th century is rather beside the point, no law ever said anyone had to sing it).

The American anthem is even sillier, praising a flag. (They oughta use "This Land Is Your Land" and then they can argue interminably about whether to use the last verse).