Why does the armed forces need to pledge allegiance to a person?
> In the UK, it's the monarch, not the government. That balance of power (military v political/legislative) gives you national stability.
I don't think there's much evidence of that.
> You don't want one person having both
Why not?
> Its the main reason royals serve in the armed forces.
The main reason the royals serve in the armed forces is that the royalty (and even the broader nobility) is a remnant of what is notionally a warrior elite that is traditionally barred from servile labor but has position of authority ultimately grounded in military function. The substance of both the authority and the distinct warrior class is almost entirely extinct, but traditions remain, including the tradition that it's pretty much the only thing that looks like work that senior royals are permitted to do, as anything else in government would be seen to violate their distance from that function and anything else would be seen as demeaning the monarchy.
Mind you - he was an officer and from a rather posh guards regiment so that's kind of what I would expect him to say.
Mind you - the UK can only have a standing army with the express permission of Parliament:
This requirement only seems to apply to British Army, the Navy and Air Force are exempt. W good example of how unimportant the pageantry is.
In contrast, the 'Royal' Navy was created expressly by the monarch so allegiance is implied.
You don't want one person having both.
Its the main reason royals serve in the armed forces.