Combatives training is a valuable tool for U.S. Army commanders because it improves unit cohesion and lethality. I believe hand-to-hand combat will also prove consequential in future armed conflict.

In an era of hypersonic missiles, stealth fighters, and nuclear subs, it’s hard to picture sailors going toe-to-toe with the enemy on a ship’s deck. Yet during World War II, the crew of a brand-new ...