It SHOULD be called the Department of War, as it was originally, since it makes its function clear. We are a society that has euphemized everything and so we no longer understand anything.

It's a funny thing that the most war-loving people and the most peace-loving people both love calling it "Department of War" - just for different reasons.

But the reason for "Department of Defense" name was bureaucratic. It's also not true that DOD is hard to understand.

The Department of the Army is what was previously called the Department of War. The Department of Defense is new, dating to just after WWII.

Naming is important because it intuits what we expect to do with a thing. The Department of Defense invading Greenland is more invocative to inquiry than the Department of War invading Greenland because that's what a department of war would do.

It's one of the reasons why people get annoyed at jargon or are pissed off about pronouns, because it highlights that they should be putting mental effort into understanding why they're current mental model doesn't fit. It's much easier to ignore and be comfortable if there's not glaring sirens saying you've got some learning to do.

Most of us can't (or won't) be aware of everything that should be important to us, having glaring context clues that we should take notice of something incongruous is important. It's also why the Trump media approach works so well it's basically a case of alarm fatigue as republicans who would normally side against any particular one of his actions don't listen because they agreed with some of the actions that democrats previously raised alarms about.

Doublespeak, so to speak.