When I joined the Air Force in 1977....Vietnam had been over for roughly 3 years. Over the next ten years of my life, I'd continually run into some guys who'd been in SW Asia, and the topic of the war would come up. By the late 1980s...most of these people were gone (either via retirement, alcohol issues, or stress issues).
I worked with major who'd been through five DWIs and had been directed to Panama for the final four years of his career (the AF was doing him a favor....at least in their mind). All he had to is show up 2 times a week to fly for 45 minutes, and pretend his way around as 'safety-officer'. His wife was supposed to drive him around....they trusted him enough to fly a plane, but not to drive a car (go figure).
On a late afternoon, after a beer or two....he'd launch into any of 300-odd stories of his two tours of duty (Vietnam and Thailand). The tours and the events stuck with him....ten to fifteen years later. I often wondered what happened to him after the retirement. Maybe he settled down in Florida and would spend afternoons at the VFW....consuming cocktails and sharing war stories with other vets.
Once Desert Storm started up....the forever wars started. There were countless little deployment activities that consumed tens of thousands of GI's. Some were fairly serious, with stringent rules of no booze, and marginal safety. Some were in zones where beer readily flowed and it was almost a party zone.
A year in these war zones....would consume some people. They would return back to their normal job and be someone you never knew. They would complain about sleep (sometimes never getting more than three consecutive hours of sleep). Some would have hearing problems from the AC unit next to their tent which ran 24 hours a day, for the whole 365 day tour. Some would be addicted to Monster high-caffeine drinks....guzzling down six a day.
Officers would be told over and over....to advance your career....you needed a tour to a forever war....to be at this level, or guide x-number of folks. Two months into the tour, they'd be writing a causality report....explaining how these five guys in the unit were wounded in action....and that each deserved such-and-such medal. Around six months into the tour, you'd lose your prospective and start counting days till your tour ended.
The problem was....forever wars simply led onto a second forever war, and then onto a third forever war.
I worked around a Marine who'd done five tours since 1997. He had four years to go for retirement and figured he'd have to do a minimum of one tour....maybe two....before the end. He had a list of ailments...all documented...all related to back issues. He figured a year after retirement....he'd turn the info over and collect a disability payment on top of his retirement. Resolving the issues? Other than pain-relievers, there wasn't much the Marines could do.
The four years? Trump kinda led the Pentagon down this unique path. He wanted the forever wars to actually end. The generals? Well....they've been conditioned to favor the forever wars because there's money to be made for hardware or contracting. So Trump has basically led the other path....the forever war will end, and you will just pack up to return to the US.
With Biden? I suspect his people in the background favor the forever war business....having little understanding of the impact, consequences, or cost-factor.
As for the folks in Afghanistan? The sad thing here is that you only a thousand dimwits with juvenile 'war-zest' in their gut, and they can make everything miserable for the nation. You'd basically need to lead the thousand out to some life end-point and put them out of their misery....to settle the safety and security for the 99.99 percent of Afghans.
On this one topic, Trump is correct. This routine of the forever war 'dance' has close down. Enough is enough.