For the extremely simple reason that it is slavery to the State:
Prince Harry has called for the country to bring back National Service after revealing his time in the Army 'saved' him.
As he prepares to leave his 10-year military career next month, he has revealed his life could have been different if he had not served in the Army.
He said: “I dread to think where I’d be without the Army.
“Bring back National Service – I’ve said that before. But I put my hand up, as I said to the kids today, you can make bad choices, some severe, some not so severe.
“Without a doubt, it does keep you out of trouble. You can make bad choices in life, but it’s how you recover from those and which path you end up taking.
"I did it because since I was a kid I enjoyed wearing the combats, I enjoyed running around with a rifle, jumping in a ditch and living in the rain, and stuff.
"But then when I grew up, it became more than that, it became an opportunity for me to escape the limelight."
That military service has been good for Prince Harry we're entirely willing to agree (although we would point out that this is rather the purpose of Princes, that military stuff). Similarly, that many who do military service benefit from it we've no doubt at all.
But the imposition of enforced military service upon all is something we're adamantly against. The Army doesn't want it (and as with last time, that's where almost all would end up), we can't afford it (not so much paying people peanuts while they do it, rather the loss of what they would have been doing otherwise) and when we did have it it bred nothing but contempt for the entire society that imposed it.
But hugely more important than any of those practical reasons is the moral one. National Service is slavery to the State. For 18 months, whatever the service period is, they must put aside their lives to become a cog in the designs of the politicians. This is not something that a civilised society does, impose such loss of liberty upon all.
That military service benefits those who volunteer is just dandy. But the important word there is "volunteer". The imposition of conscription upon all, whether military or the various "compulsory community service" options being bandied about is an abhorrence.