You can call back to Major General Smedly Butler and his "War is a racket".
WWII got the US out of the remnants of the great depression. The massive industrial push for both our equipment and the lend-lease model was a massive infusion into our economy. It was so huge, that it never really stopped. Our economic model and system was sick, and the military industrial complex(dramatic but apt term) was a large-scale make-work endeavor that would double as an expression of global power and propaganda both home and abroad.
One could take this and begin to see that conflict may be instigated for the sake of the MIC. Al Qaeda wasn't in Iraq, but it didn't stop us from invading, making up claims of WMDs that couldn't be substantiated, then destabilizing the region. The power vacuums then create later conflicts, for more military machinery to be built for.
The HMMV was continued to be sent to the middle east long after we all acknowledged they were death traps for soldiers. Same thing for certain tanks, they kept making them to keep people employed.
The big thing now, is the propaganda worked too well, and we became too focused on giving as much taxpayer dollars to lockheed and raytheon as we could.
We didn't win Afghanistan, Iraq left ISIS in it's wake. But the point wasn't to win, it was to brutalize(externally facing propaganda) and sell weapons. Since the purpose of conflict was so extremely warped to enable the MIC, winning didn't matter, and our ability to win corroded greatly. We won WWII because of our logistics. Those logistics have broken down as we deindustrialized and moved to more and more expensive "smart weapons". Those smart weapons made promises of warfare so advanced, you only need a handful. So we pay millions per missile. Then we use them all up defending against dumb weapons, and we lack the capacity to make more.
Our military is in effect a paper tiger. The real threat of the US military is mass civilian casualty. If we can't take them out with drones, land invasion would be a catastrophe, and then actual WMDs would be deployed to save face. Nuclear genocide is the US military's only real remaining card, as we've devoured the propaganda and rested on our grandparent's laurels while losing sight of what earned the respect.