How did the cars and tanks get started by the soldiers? Any soldier could need to drive and car or tank at any time, or even the enemy’s. I’m sure they don’t have a key, so how do these get started without any risk of them being stolen?
When I was in the USCG in the 1980s each of our GV (Government Vehicle) was started by a key. Whichever department had a particular vehicle had possession of the keys.
They actually have a key ignition. At least, every land vehicle I was in. The ships, being a tad bigger, were kind of hard to pilfer what with there always being someone, including the armed Marine detachment, aboard. Tanks and other armored vehicles were either manned or kept secured in a military motor pool.
“Any soldier” does not need to “drive [any] car or tank at any time”. Soldiers, Sailors, Airmen, Marines, etc. get trained in driving the vehicles they’ll be needing to drive. The immediate practical reason for this is that an incompetent tank driver can do a lot of damage to the wrong things or wrong people.
This is NOT what Call of Duty has taught me.
**How do vehicles in the millitary start? **
When a mommy military vehicle and a daddy military vehicle love each other very much…
Military aircraft certainly don’t have keys (though some that operate in forward areas may have door keys).
The old weapons carriers and the like often had a battle switch instead of a key. Anybody could jump in, flip the switch and hit the starter button. That was in a combat arena, of course. Stateside and peacetime areas, vehicles have keys so they can be dispatched and controlled.
Army trucks do not have key starts. There is a toggle switch. The steering wheel is locked with a cable and padlock when not in use.
When I get on a computer I’ll find a pic. I’m mostly seeing pics of trucks modified for key start when I search now.
What happens if the guy with the key gets lost or captured? Do they issue keys to everyone in the unit who is qualified to drive the vehicle so that they can take over, or do keys only go to those who are actually expected to drive? E.g. how often do qualified drivers end up not being able to drive due to lack of keys? “Well, Cpl. Jones is certified to drive the tank too, but unless Sgt. Smith makes it back with the keys, we’re out of luck.”
Must not be my normal sarcastic self when someone seems to think civilian type vehicles would be started in the same way WAR vehicles would, like heavy armament.
Ever watch oh say WWII movies with lots of armor? They might be laagered or grouped together in a depot with ARMED guards on duty in certain circumstances, but not all when stationary for prolonged periods of times and needing a key would be irrational to me because of the possibility of them being misplaced and well its a Tank so kind of, but not impossible, to steal.
I dont know about APCs but Humvees and the like would have keys, probably or a toggle if not.
US Army trucks, tanks, HMMWVs, and other tactical vehicles use a switch to start. The only key, as Loach mentions, would be to remove a cable and padlock wrapped around the steering wheel. Here is a picture of the ignition switch for a Humvee:
The only thing I’ve seen that uses normal keys are standard fleet cars. We call them GOVs (government owned vehicles, pronounced Gee Oh Vees) or TMPs (Transportation Motor Pool). Also sometimes called GSAs (No idea). These are the normal, everyday, off-the-lot, cars, trucks and vans a unit might have. Recruiters, for instance, aren’t driving around town in hummers, they have normal civilian cars that use normal civilian keys.
Everything else uses a push-button or a switch.
They put saltpeter in the fuel to prevent that now.
Here is a closely related thread from 8 years ago: Do big vehicles have ignition keys? - Factual Questions - Straight Dope Message Board
It’s not exclusively about military vehicles, but they do get covered.
I am familiar with the M-48 tank. Yeah, I know, its an antique. There was no key. But, the starting process needed some training. You had to start a small engine, then you had the power to start the main engine. So people, just off the street, probably couldn’t steal it.
But nowadays, with the internet, this information probably exists. But you would have to find a M-48 tank that wasn’t in a museum.
That would be really cool, though. 
Around 1987 I was driving in rural Georgia near Ft. Benning and found a US Army bus parked in the middle of a single-lane bridge, completely blocking the road. I looked inside and there was a key hanging in the ignition lock.
I’ve been told that this is unusual and most military vehicles have toggle switches installed instead of keyed ignition locks.
Busses have keys, since they’re just standard off-the-lot busses. I got pretty good at driving a bus. As a drill sergeant, I would often have to sign out the buss keys to shuttle privates out to the range or barber.
On a related topic i believe all tractors in the UK start with the same key. Or maybe they dont have a key, jst a start button.
Should not be as surprising as all handcuffs can be opened by the same key.