The idea that the Kamikaze pilots received large doses of methamphetamine prior to their attacks is a common claim in popular literature. Norman Ohler's questionable book Blitzed: Drugs in the Third Reich observes in a footnote that Japan's suicide pilots received crystal meth under the trademark Philopon/Hiropon. Likewise, many online exposes of the history of meth such as those by Vice.com casually mention the connection between these stimulants and the Kamikaze pilots. This drug use, however, is not the whole story, and focusing only on the stimulants used by the Kamikaze tends to obscure important facets of drug use by many combatants during the war.

While surviving documentation from Kamikaze pilots tend not to mention either Philopon or Hiropon, it was possible that more than a few pilots for Tokko missions received these drugs. The same was also true for a number of Japanese who undertook conventional attacks. Philopon, which was more akin to benzedrine, was one of several stimulants the Japanese used to combat fatigue. Much as the term "aspirin" can be used as a placeholder for oral painkillers or the trademarked Bayer product, Philopon could refer to any number of stimulants available for Japanese during the war. There were a number of pills, often mixed with green tea and stamped with the imperial crest called Senryoku Zokyo Zai (drug to inspire fighting spirit) that contained a variety of uppers. This was not limited to combat troops. A number of night-shift factory workers and construction workers received uppers to complete urgently-needed projects. Aside from being issued by the state, these drugs were also available over the counter to the civilian population in the Home Islands. The result was that Japan at war's end had an enormous stockpile of uppers such as methamphetamine which filtered their way into the black market and led to a major drug epidemic in the postwar decade.

This above would seem to validate the at times hyperbolic claims that Japanese wartime excesses were built on the backs of illicit drugs like meth. The problem though is that examining Japanese or German drug use in isolation produces a distorted picture. The fact is the Axis were not alone in seeing the value of uppers for combat purposes. The British and Commonwealth forces used Benzedrine tablets in enormous numbers after reports filtered in on the effectiveness of Pervitin by German forces. The RAF conducted extensive studies on uppers and long-range bomber missions often had pilots hopped up on these pills. Bernard Montgomery was incredibly impressed by a 1942 field experiment between drugged and undrugged soldiers that he saw Benzedrine as a weapon to defeat Rommel and ordered massive quantities of the drug before el Alamein. The Eight Army in the Mediterranean theater would subsequently allow doses of amphetamine higher than the dose recommended by RAF studies on the basis that the drug improved morale and performance. The US followed a similar trajectory as their British allies. The US Army Surgeon General issued a cautious endorsement of amphetamine use by frontline troops in extreme situations, but frontline generals and combat troops often distributed these drugs in dosages much higher than the medical professionals thought advisable. The USMC troops at Tarawa received Benzedrine as did other troops during Pacific landings. The British and American medical studies of various uppers often found that they did depress anxieties and fear, amphetamines in their various forms were not war-winning tools. But the medical professionals' cautious endorsements of these drugs masked their somewhat more extensive use by Allied frontline troops.

One of the problems with books like Blitzed- and check out /u/commiespceinvader 's take on Blitzed in their answer here - is that they present Axis drug use out of its full context. The implication of some of this pop history is that illicit drugs enabled the irrationality of Tokko suicide attacks or the Einsatzgruppens' massacres. This is tapping into wider discourses about the connection between drug use and behavior harmful to society (eg Breaking Bad). Thus the irrationality and human rights abuses of the Axis become subsumed as part of a drug crisis. But the problem is that the Anglo-Americans used these drugs in significant quantities too and do not get the same treatment by pop historians. There are not many books out there ascribing the firebombing of Dresden to the use of Bennies by a number of Anglo-American bomber pilots and planners. While there is a productive line of inquiry and research into whether or not uppers contributed to the savagery of the war on both sides, extrapolating the abuse of uppers to explain major events in the war like Japan's suicide tactics is not very sound history.

Sources

Caprio, Mark E. Democracy in Occupied Japan The U.S. Occupation and Japanese Politics and Society. Routledge, 2009.

Derickson, Alan. "“No Such Thing as a Night's Sleep”: The Embattled Sleep of American Fighting Men from World War II to the Present." Journal of Social History 47, no. 1 (2013): 1-26.

Edström, Bert. "The forgotten success story: Japan and the methamphetamine problem." In Japan Forum, vol. 27, no. 4, pp. 519-543. Routledge, 2015.

Rasmussen, Nicolas. "Medical science and the military: the Allies' use of amphetamine during World War II." Journal of Interdisciplinary History 42, no. 2 (2011): 205-233.