Hitler's Wehrmacht did some studies (on unwitting human subjects, naturally), and concluded that as far as waging illegal war is concerned, methamphetamine is great for productivity: https://www.psychiatrictimes.com/view/methamphetamine-dictat...

U.S. Air Force, being tasked with a somewhat similar job, came to similar conclusions: https://pubmed.ncbi.nlm.nih.gov/7661838/