One problem is that if you go on building for WW-IV, WW-V, WW-VI etc. long enough, sooner or later, it's gonna happen.....
How would we even begin to number the wars? One could argue that this is WW III. German bankers and elites are finally meeting some (not effective enough) resistance to their takeover of Europe. Globalist forces hellbent to control land and resources have decimated the Mideast. Following your logic, until spending is shifted from machines to blow things up to improving infrastructure and quality of life, we're getting what the global elite are paying for.
Wars are born of weakness, not strength. The post WWI treaties limited American naval strength and provided an opening for the Japanese, who largely ignored the limitations the treaty placed on the Japanese navy.
The big issue is not the size of our military, rather it is that we allow companies like Lockheed to use programs like the F35 as an ATM for extracting money from the American taxpayer.