This is the fourth article in a series of articles on redefining war, the battlefieldBattlefield, and the armyArmy in the twenty-first century that has been ongoing since October 7, 2023. This article discusses the weapon that changed the post-modernBattlefield battlefield—the unmanned aerial vehicle. The unmanned aerial vehicle opened a new chapter in aerial warfare, changed the face of warWar in the twenty-first century, and transformed mini-armies of terrorist organizations into armies with advantages over regular armies- organizations like Hamas, Hezbollah, Houthis, and Iraqi Shiite militias. As a result of the dronesDrones, weak regular armies like the Ukrainian and Azerbaijani armies have been able to win or partially win against strong armies like Armenia and Russia. Our research period takes place between the second Nagorno-Karabakh war in 2020, the Russian-Ukraine conflict that broke out in February 2022 and continues to this day, the attack by Hamas on Israel on October 7, 2023, and the ongoing Israel-Gaza war. Additionally, Iran has waged a proxyProxy warWar against the State of Israel (and the US) since October 7, 2023, with an emphasis on Hezbollah, Houthis, and Shiite militias. A comparison table and research methodology are presented between the drone forces of all the mentioned “armies” and the drone forces of all the other armies.