Making a lot of money? National pride? Belief in the superiority of liberal capitalism? A historical perspective that focuses on the difficulty the American military had mobilizing in the 19th and early 20th century? A sincere fear of the outside world and belief that strong military spending can protect them?

I may be missing Vatz point, but I don't think Bitzer would define "positive modification" as an absolute unquestioned good, but that someone has to have some cause for desire. The MIC has a load of very obvious reasons behind it, reasons I might not personally agree with or be persuaded by, but it has a whole bunch of really obvious "positive modifications" that can be found.