Why do soldiers have to shave?

+ 1..The Gas Mask thing is Not a Hypothesis..Men were Killing Each Other for a Life Saving Razor in the Trenches..A Gas Mask Wont Seal with a Growth..Also..The Royal Navy are Traditionally Allowed to Grow a Beard because the Beard Could be Grabbed to Help a Man Going Overboard..

So..Different Reasons & Different Traditions..Also..I Served in the Falklands in the Royal Marine Commandos & there was No Pressure to Shave in the Field..I Didn't Shave for Over 3 Months or More..More Importantly Shaving in the Field Can Cause All Sorts of Problems with Skin Infections Etc..

Billy
 
I recall the gas mask hypothesis was discussed on QI once; indeed, supposedly soldiers in the British Army were required to have moustaches (though not bears) through much of the 19th century, and this lasted through the Second Boer War.

Yeah, prior to the 19th century, every non-commissioned soldier had to have a bear. You had to keep it groomed and well fed, otherwise your bear may eat one of your fellow soldiers. Since soldiers spent a lot of time camping in the woods during this period of history, this is where the expression "does a bear shit in the woods?" comes from.

It was optional to shave your bear.
 
What is a tash?
 
We're talking Scottish sailors, right? A Scotsman once said that to really enjoy the pleasures of sheep, you have to dick them at the edge of a cliff so they push back. Is that true, @Fergiebilly?
As a fan of Aberdeen FC I couldn't possibly comment

On the question of beards in the military - my theory is the routine of shaving when joining helps install a routine and discipline. Also cleanliness/hygiene is an essential characteristic, if injured - less bacteria to infect wounds and more chance of faster return to full fitness. If my memory is right the discipline in the Royal Navy re cleanliness of ship, personnel and kit stemmed back to the Napoleonic wars when vast numbers of the opposing forces died due to wound infection and general disease.
 

Remember that no one on Earth knew what definitively caused infection until the late 1800's and even then no sulfa drugs appeared until late in WWII.
 
I have little doubt that this is to instill discipline.

I once heard it said that "discipline is only necessary where something stands to be lost through its absence". And nowhere is more to be lost than in the field of warfare - namely, life itself.

I have not served in the forces myself, but I understand that discipline there extends far beyond personal appearance - to uniform, firearms maintenance, an orderly bunk; to all areas of service life, in fact.