But imagine this
What if that massive deficit spending had been put into things that actually benefited the economy, instead of war? What if we had built highways, schools and universities, hospitals? What if it was invested in R&D for energy, technology and things that actually laid the foundation for future growth, instead of bombs?
Deficit spending is not a bad thing as long as it is done intelligently. For instance, if a society cannot afford to build a highway system, it is STUPID to not borrow the money to do it because the economic and societal benefits will be so great later on. Businesses borrow money all the time to expand their capacity. Governments are no different.