we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military-industrial complex
By 
I’m not saying this is the only reason the Blob has gone to war with Biden because he ended their latest idiotic crusade, but it’s certainly a reason:
The failure of the American mission in Afghanistan became deadly apparent last month when the Afghan army collapsed as the Taliban took control.
But the generals who led the mission — including McChrystal, who sought and supervised the 2009 American troop surge — have thrived in the private sector since leaving the war.They have amassed influence within businesses, at universities and in think tanks, in some cases selling their experience in a conflict that killed an estimated 176,000 people, cost the United States more than $2 trillion and concluded with the restoration of Taliban rule.
The eight generals who commanded American forces in Afghanistan between 2008 and 2018 have gone on to serve on more than 20 corporate boards, according to a review of company disclosures and other releases.
[…]
McChrystal is the runaway corporate leader. A board member or adviser for at least 10 companies since 2010, according to corporate filings and news releases, he also leverages his experience to secure lucrative consulting contracts on topics distant from defense work, such as managing the coronavirus pandemic for state and local governments. The general, who was dismissed after being quoted in 2010 disparaging then-Vice President Joe Biden, has made millions from corporations, governments and universities, commanding six-figure salaries for some of his board positions and high five-figure speaking fees.
[…]
The University of Nebraska at Lincoln was facing the prospect of curtailing research programs because of budgetary pressure in 2013 when it invited McChrystal to campus. For a keynote address at the university’s “Building the 22nd Century” conference, the university proposed what it understood to be his standard speaking fee: $62,500.
There was a hitch. Because of a board meeting in Chicago earlier that day, McChrystal required a private jet, a representative from the general’s speakers bureau, Leading Authorities, told university officials in emails obtained as part of a public records request. The fee would have to be higher: $80,000.
It’s a nice racket!
No matter how dire the financial position of universities, there always seems to be money available to 1)hire high-priced consultants (especially those in consultancies that may have use for academic administrators) and 2)give the people who presided over failed wars enormous sums of money to do nothing in particular.