During World War II, the Allies used recon by fire to find the location of the enemy by shooting and seeing where they shot back from. This tactic was used instead of the older method where tanks would follow behind soldiers on the ground, which was slow and didn't put enough pressure on the enemy. The new way was fast, and soldiers would shoot their weapons constantly as they moved forward to keep the enemy distracted and aim off target. They also used this tactic when they were travelling with trucks that had big machine guns.