In some movies, you see soldiers (usually Marines) standing guard in front of an important doorway. Usually two, they stand, guns ready, staring straight ahead.
While it dramatically shows it is an important secret room/computer/meeting, do real soldiers do this? Stand there wooden-faced for hours or all-day in front of a door? Has anyone here done this while in the military? How do you keep from getting bored?
Not so much nowadays. Soldiers are just too expensive, and automatic systems have a lower failure rate than guys with guns. The fellows you see guarding are mostly there for ceremonial reasons.
The Marines guard the White House, but the White House police do most of the ‘real’ protecting. The Army guards the Tomb of the Unknowns, but they have civilians to keep people from molesting the guards.
Let’s put it this way, nuclear weapons are guarded by automatic systems controlled from an air-conditioned room backed up by a well-armed guard force. That force does not wear nifty uniforms and carry chromed bayonets.
Pull guard duty? yes done all the time. At attention for hours? No. Usually we get a couple chairs and pay attention. If people approach then we get up take care of them, and sit back down. Think of an armed receptionist. Like Paul in Saudi said. Electronics work better for alot of it these days.
-Otanx
In an episode of The West Wing a guy attempts “suicide by police” by firing a gun at the White House. Within moments of the firing, a well-armed Marine in full combat dress appeared in the Oval Office to guard the president. Supposing that this fiction has some basis in fact, where would such a Marine come from. Is there really some poor Marine sitting around waiting for mayhem to ensue?
Marine in full combat dress? All the military guards I saw around the White House (I used to live in Arlington, and would take quite a few trips into DC) were wearing their dress uniforms.
The posts for Marines at US Embassies are armored reception booths, like Otanx wrote. They generally do not wear dress uniforms. They can be ready for combat in a short time (more than moments, less than minutes).
The chaps guarding Buckingham Palace stand motionless in boxes for long periods of time. Tourists are welcome to stand alongside them and have a picture taken.
Every so often the guards march a short distance and return. (I assume they would get exhausted standing still for hours at a time).
‘When The Queen is in residence, there are four sentries at the front of the building; when she is away there are two.
The Queen’s Guard usually consists of Foot Guards in full-dress uniform of red tunics and bearskins…’
Inside the White House there are marines with regular combat gear stationed. The dress uniforms are nice but there’s also some guys ready for more than parade.
Army regulations state that a soldier pulling guard should work 2 hours on, four hours off for no more than a 24 hour shift. So in 24 hours, he’ll guard 8 and be off 16.
Sometimes I wonder if ANYONE realizes this. Once, I had to pull guard for 36 straight hours. That was in a shack with no heat and no chairs in dead of winter, in Korea (like 6 degrees outside). And to top it off, some asshole wanted to get pissed off that I was sitting on the floor. God, I don’t miss that place a bit.
I’ve pulled plenty of quarterdeck watches and pier sentry watches while in the Navy. Many of these were spent with a holstered .45 or 9 mm.
Actually, that would be a pretty lousy procedure for ‘guarding’ something. They would soon be daydreaming, and not alert & at guard.
For real guarding, watch the Secret Service guards around the President. They are constantly watching & scanning the crowd, moving & repositioning themselves around the President and in relation to each other. Very alert and active. Not at all like in the movies.
What you describe is commonly called ‘honor guards’. They are there more for honorary reasons, not because they are actually an effective guard.
I once visited a Navy facility in Iceland during the 1980s. We had to enter the secure command center. The Marine on guard duty was definitely a) alert and b) armed. I wondered what he would do with that grenade launcher. The command center was a separate building built inside a larger building. So the guard was inside even though he was outside the building he was guarding. But if he had fired that launcher, it would not have been pretty. 
BTW, he didn’t recognize our credentials so we had to wait for the Navy officer to come outside with the rulebook. Even the officer wasn’t arguing with the guard, he was just showing him that our credentials were OK. We eventually got in, but it was definitely “by the book”!
I believe this is relavant to the OP. Many of you will probably remember these.
The 11 General Orders of a Sentry