In the Ukrainian city of Lviv, students and artists make Molotov cocktails in an industrial space that used to host raves. In a suburb of Kyiv, a retired economist shows a CNN reporter her stock of the incendiary devices, explaining that she built them after searching for instructions on Google. In Dnipro, women gather outside to assemble the makeshift bombs.

Citizens all over Europe’s largest country are preparing vast quantities of Molotov cocktails to fight off Russian forces. For nearly a century, the device—called also a petrol bomb or a gasoline bomb—has been the most accessible weapon for underdogs fighting against a technologically superior enemy. Molotov cocktails are much more effective than stones, but not much harder to come by. All that’s needed is a glass bottle and a few flammable ingredients.

Russian tanks have long been the targets of Molotov cocktails. Right-wing nationalist rebels in the Spanish Civil War first used petrol bombs in 1937 against Soviet tanks supplied to the Republican government. In one encounter witnessed by an astonished British brigadier general, the homemade bombs managed to destroy nine tanks. Soon the Republican Army and the international brigades fighting by its side were using them too.

But the people of Finland were the ones who came up with the name. When Soviet forces attacked Finland in 1939, Vyacheslav Mikhaylovich Molotov, Stalin’s foreign minister, claimed the warplanes were airlifting food to the country, not dropping bombs. The Finns responded by dubbing the bombs “Molotov’s bread baskets” and offered to provide drinks—or cocktails—to go with them. State liquor factories had already switched from making vodka to preparing bulk quantities of the improvised incendiary devices, which Finnish troops used with great effect against Soviet armor. The name “Molotov cocktail” stuck and quickly spread around the world.

During World War II, Britain seized on Molotov cocktails as an important defense against the feared Nazi invasion. In 1940, Tom Wintringham, a veteran of the Spanish Civil War’s international brigades, published a guide to Molotov cocktails in the popular British magazine Picture Post. After providing a recipe for the devices, he told readers how to use them.

“Wait for your tank. When near enough, your pal lights [the] petrol-soaked corner of the blanket. Throw the bottle and blanket as soon as this corner is flaring. (You cannot throw it far.) See that it drops in front of the tank. The blanket should catch in the tracks or in a cog-wheel, or wind itself round an axle. The bottle will smash, but the petrol should soak the blanket well enough to make a really healthy fire which will burn the rubber wheels on which the tank track runs, set fire to the carburetor or frizzle the crew.”

The British government trained the Home Guard—men too old to fight in the regular army—in the use of what were called “cocktails à la Molotov.” In a training video volunteers were shown how to build a barricade to stop a Nazi tank before bombarding “old nasty” with Molotov cocktails.

The U.K. also mass manufactured “model 76 grenades”—Molotov cocktails with rubber dissolved in them to make the fuel adhesive and a white phosphorus ignition system that did not require the user to light a rag. Some six million of these grenades were made, with boxes stashed all around the country to allow British citizens to resist occupation much as Ukrainians are doing today. As recently as 2018, these stashes were still being uncovered by construction workers digging foundations.

Following World War II, when the Hungarian people rose up against Soviet control in 1956, the Molotov cocktail was their weapon of choice. They destroyed as many as 400 tanks before the rebellion was crushed.

Since then, Molotov cocktails have been used worldwide during protests and armed conflicts. Czechoslovakians heaved them at invading Warsaw Pact troops during the Prague Spring. Students chucked them at French police in Paris. Palestinians hurled them at Israeli soldiers. Sandinistas threw them at the National Guard in Nicaragua. Anti-shah protestors lobbed them during the Iranian revolution. Demonstrators in Hong Kong flung them during the recent Chinese crackdown. In the U.S., they’ve been ignited during racial protests.

When people feel the odds are stacked against them, Molotov cocktails are the weapons they still reach for, the weapons that undermine—with bright flashes of flame—the narrative of those with seemingly overwhelming power.

So it goes in Ukraine as well. The Kremlin claimed that Russian troops would be warmly welcomed in Ukraine. Instead, said Ukrainian First Lady Olena Zelenska in a recent statement, “they have been shunned with Molotov cocktails.”