On the other hand calling it "Department of Defense" seems quite whitewashing of what it actually does.
Yes, invading Hawaii was part of imperial Japanese planning. If you don’t understand that defense spending is still worthwhile even if you don’t blow anything up with it, I’m not sure how we connect.
You're basically saying the US don't need a Department of Defense because the Department of War is doing such a good job.
How do you know that's the reason? There are many countries with very low defense spending that haven't been invaded since WW2.
I was just saying that the purpose of the Department of Defence is to spend the "defence budget".