Artillery: Artillery has been used in warfare for centuries, but it became much more powerful and destructive in the 19th and 20th centuries. New technologies, such as rifled barrels and high-explosive shells, allowed artillery to fire shells with greater accuracy and destructive power. In World War I, artillery was used to bombard enemy positions, and it was responsible for a significant number of casualties.
Tanks: Tanks were first used in combat in World War I, and they quickly proved to be a powerful weapon. Tanks could cross trenches and other obstacles that had previously stopped infantry advances, and they could provide mobile firepower. In World War II, tanks were used extensively by both sides, and they played a major role in the Allied victory.
Aircraft: Aircraft were first used in combat in the early 20th century, and they quickly became a major force on the battlefield. Aircraft could be used for reconnaissance, bombing, and strafing, and they could inflict heavy casualties on enemy troops and equipment. In World War II, aircraft played a major role in the destruction of German cities and the defeat of the Axis powers.
Nuclear weapons: Nuclear weapons are the most destructive weapons ever created by humanity. They were first used in combat by the United States in World War II, and they instantly killed hundreds of thousands of people. Nuclear weapons have not been used in combat since World War II, but they remain a major threat to global security.