These are cases that threaten security of soldiers and citizens, so self defence applies, so guess what.

Soldiers didn't immediately question who was taking stuff out of their trucks? Are they idiots? And when they realized what happened, they tried to chase down the ATV? Why the f--- didn't they SHOOT the thief? Aren't they armed? Letting high-tech weapons fall into terrorist hands! What total idiots. Shoot a few of the thieves and you'll see how quickly this stops. If all else fails, keep two soldiers with the equipment at all times. And if anyone approaches, guns up!

If they let people walk up and steal their guns what will they do in the thick of battle?