The Japanese military used mass suicides and kamikaze missions to intimidate the Americans from advancing in World War II. It's not so much barbarism against themselves, I'd say that's more of like a manipulation strategy to get their soldiers to be willing to sacrifice themselves. An example would be during the Vietnam War, how they'd use napalm, for example, to level all the forests so that the Viet Cong couldn't use the jungle as a guerrilla warfare thing or interrupt supply lines. Another example would be the Chechens resisting the Russians,. They would attack the Russians and then retreat into the forest... Then the Russians cut down the whole forest so that they couldn't mount a resistance movement