In trying to understand if I'm missing something, I looked up what newspeak means. I (as well as probably a few other commenters based on the contents of their comments) was under the assumption it meant "new speak" meaning it's something new.

In case anyone else reading this was not aware of this, this is what I discovered.

It's a term from George Orwell's 1984, describing a language used to make thoughts unthinkable by removing words from the language. It has nothing to do with "age of the term."

Hence, Dept of Defense is indeed newspeak. Dept of War, while being a new name for the dept, is too literal to be newspeak.

Thanks for the opportunity for me to learn something!

Department of Defense has historically been a prime example of newspeak.

I think Department of War is also newspeak. Or at least, they didn't change the name just to get the name in line with the amount of war the department does.

They changed it because they wanted to do more even more war. The amount of war the department does under the name "Defense" has been status quo for a long time, and my take is they wanted us to think of them differently so they could do even more war, which they have since been doing.