However, the reply from upstairs was amazing-which army shouted "comrades, retreat!" " Before the battle. Is there such power?

Generally speaking, the tradition of the US military is to shout slogans of troops, such as the famous rangers. Before departure, everyone will get together, and the officers will shout: Ranger, lead the way! (literally, the rangers lead the way, as Washington said, literally, the rangers charge first), and then someone else answers: hoo-ha!