Explanation: During the Siege of Alesia, Gaius Julius Caesar, of later dictator fame, besieged the Gallic leader Vercingetorix by building a wall around the walled city of Alesia.
When Caesar heard that a massive Gallic army was coming to reinforce Vercingetorix, instead of lifting the siege, Caesar built ANOTHER wall - this one around his siege camp, to keep the reinforcing Gauls out.
When I heard of that chad move it really struck home that the Roman superpower wasn’t their infinite spawning exploit, or the organized military formations. It was the extreme engineering spec.
Deadliest military weapon is a soldier with a shovel, and an angry NCO to make them use it.