In the spring of 1940, the German army barely slept on its way into France. And the reason why is one of the strangest stories of the war. In 1938, a Berlin pharmaceutical company called Temmler started selling a new pill called Pervitin. It was methamphetamine. You could buy it over the counter. It was marketed as a pick-me-up for tired workers and housewives, and it took off fast. The German army noticed. A military physiologist named Otto Ranke tested it on medical students and found they could stay awake and keep working through exhaustion. He saw the potential right away. He also started taking it himself to get through his own long workdays. When Germany invaded Poland in 1939, soldiers were already using it. A 22-year-old private named Heinrich Böll kept writing letters home asking his family to send him more. Decades later, he won the Nobel Prize for Literature. Then came France. Between April and July 1940, the Wehrmacht and Luftwaffe were shipped around 35 million tablets. Troops nicknamed it "tank chocolate" and "pilot salt." When the panzers punched through the Ardennes, some units kept moving for days with almost no sleep. The French had assumed nobody could get an armored force through that forest quickly. They were wrong, and France fell in about six weeks. The cost showed up soon after. Reports of heart failure, collapse, and soldiers wrecked by exhaustion once the drug wore off started reaching Berlin. The Reich's health chief pushed to restrict it, and by 1941 it was legally controlled. The army kept using it anyway. Germany wasn't alone. Britain issued around 72 million Benzedrine tablets during the war, and American bomber crews used it on long missions. Japan gave its own methamphetamine, Philopon, to pilots and factory workers grinding through endless shifts. After the surrender, huge military stockpiles leaked onto the civilian market, and Japan spent the next decade fighting one of the first national meth epidemics in the world. World War II was fought with tanks, planes, and ships. But a lot of the men running them were running on speed.