In the UK we merely stand for the anthem. .. and it is not played as often as the American one is.
It is ironic that now sitting it out is viewed as a political statement , when WTS advocated it to be neutral of politics. I never saw the objection anyway, since we are told to "respect ...and honour the king " in scripture. I used to sit it out or escape the auditorium first though, just to be obedient.