The Queen’s job is to be above the fray of any particular moment’s politics and politicians. She represents the abstract institution of state, regardless of who is calling the shots today. In the same way that Americans can be loyal to America even if they hate the President... the British people have a specific human being to which they can feel the same loyalty.
I thought the Navy didn't. I recall something about how they weren't eligible for certain ceremonial roles that the army and RAF were due to never having sworn an oath to the crown.
> The Royal Navy is the oldest of the three services, and it was established by the sovereign's prerogative. For that reason, recruits have never been required to swear allegiance, but they do sign an attestation or engagement form on entry. The same applies to the Royal Marines.
I think they changed that recently- the first Navy veteran to be a Yeoman Warder ("Beefeater") at the Tower of London got the post in 2011, after the rules were changed to allow it.
