Those of us that experience the IRA attacks against service personnel, both here in the UK and in Germany, will recall that our duty was to be killed whilst bravely unarmed. Apparently being unarmed made us better, or something…. although I never paid much attention to the rambling briefs that tried to explain it all. I guess we were just grateful when they actually issued ammunition to the 'armed' guards.
I cannot see the UK ever arming off-duty military personnel. Carrying a weapon on a UK base in an operational theatre in the last 2 wars only came after armed attacks(!).