For thousands of years, military strategists have tried everything within their means to suffocate rivals while minimizing casualties of their own. In ancient times, that meant everything from launching plague-infected carcasses into enemy territory to leading the opposition into deadly traps.

With time and experience, war evolved into a far more methodical exercise, with clashing troops executing plans as complex as chess strategies. Take a look at nine innovations in waging battle that left the opposing party hopeless to resist, then tune in to National Geographic’s new series Origins (Mondays at 9/8c) for more on the ways war has shaped the world we live in today.

1. CHEMICAL WARFARE

While ammunition and weapons continue to evolve, strategists may never again be able to utilize an offensive force as sinister as the semi-invisible chemical attack, which has been a part of warfare for over 2000 years. The Spartans had their wells poisoned by the Athenians around 600 B.C., while Genghis Khan would catapult burning sulfur pitch over fortified walls by 1200 A.D. But it wasn’t until German troops launched chlorine gas at Allied forces in Belgium in 1915 that the deadly potential of poison mist was realized. Unable to recognize what was happening, the soldiers collapsed and created a near-instant pile of nearly 1000 bodies. By war’s end, 90,000 deaths and a million serious injuries were attributed to mustard and other gases. The approach was so insidious that most of the world’s leading powers signed the Geneva Protocol banning their use in combat.

2. COMMUNICATIONS

In the Middle Ages and even further back, it was difficult for commanders to pass along orders or updates with any real immediacy. Soldiers would have to hope their initial strategies would be relevant as they plowed forward. But the introduction of the telegraph in the 1800s allowed ground forces to recognize and react to changing situations, influencing both offensive and defensive decisions.

3. THE INDUSTRIAL REVOLUTION

When weapons were made by hand, their numbers were limited, but with the advent of factory manufacturing, soldiers now had more access to deadly close-range weaponry than ever. Some armies, however, were slow to catch on, sticking to formations that had no practical use when the enemy had such an abundance of firepower.

4. THE NAPOLEONIC MODEL

Napoleon was famous for instituting his bull-nosed approach to warfare: He wanted his men to swarm into battle and kill as many as possible, with little concern for what might be gained strategically. The model of sheer destruction gave him victory, but also led to untold casualties on both sides of any given conflict. Napoleon assumed deaths would occur on both sides, so he gave his own losses no mind. His approach is often referred to as “annihilation” and was carried out as late as World War II.

5. NAPALM

Used heavily in the Vietnam War, this compound was originally developed during World War II and added dangerous efficacy to bombing runs. Its expansive detonation areas resulted in significant casualties; when deployed during explosions, the tarry, jelly-like substance burned hot and stuck to skin, creating severe wounds that caused protracted suffering. In one 1945 run, Japanese forces were smothered under 690,000 pounds of Napalm, resulting in 100,000 deaths in a single evening.

6. DRONES

Thanks to the advent of unmanned aircraft, resistance against an enemy has taken on a new and potentially devastating form. Drones navigated offsite can drop into an area of conflict and take out targets with no or minimal risk to personnel—although critics charge that such attacks can come at the cost of civilian lives. As of 2015, more than 450 drone strikes were authorized by U.S. military forces.

7. GPS

During the Iraqi conflict of 1991, U.S. forces relied heavily on GPS to track and locate both opposing soldiers and their key supply facilities. For the first time, pilots and other gunners could precisely follow targets and deploy explosives with pinpoint accuracy.

8. 24-HOUR CONFLICTS

War has not always been an unceasing assault against the opposing party: Commanders would routinely plan two to four concentrated attacks in a day owing to rationed firepower. But with the advent of technology that increases an armed force’s capabilities—especially at night—it’s not uncommon to see 12 to 14 combat “pulses” (attacks) in a 24-hour cycle.

9. TOTAL WAR

In order to hasten a conclusion to the Civil War, Union General William Sherman made no exemptions for civilians on the opposing side. He tore up railroad tracks, ravaged food supplies, and burned down homes, all in an effort to dilute the resources of the men and women who supported the Confederate cause. His tactic wound up sparing lives overall by expediting the end of the conflict, and despite its (many) critics, the philosophy of “total war” has been used ever since—most notably in the nuclear bombing of Hiroshima and Nagasaki that effectively ended World War II.