The American Army was also lavishly supplied with the self-propelled artillery and ammunition it took to make these firepower-based tactics successful. When effectively employed and coordinated, these attacks negated the advantage of superior German armor and armored tactics. The effectiveness of the new fused shells exploding in mid-air stirred some German soldiers to refuse orders to move out of their bunkers during an artillery attack. General George S. Patton said that the introduction of the proximity fuse required a full revision of the tactics of land warfare.