Commentary drawing on Suez and Macmillan is just selective, emotionally incontinent straw-clutching. Wilson's decision not to follow the US into Vietnam didn't harm the transatlantic relationship in the long term, any more than Paris is still in the doghouse over Iraq. And IIRC the Cold War went pretty well for the US after Saigon, you know, when it stopped pouring resource and political capital down into a SE Asian black hole and concentrated on winning the arms race directly.
Funny how it's so easy for the commentariat and interventionist scholars to call for "low cost" presence when it's never their personal interests or families at stake. Tens of billions of dollars, the bending out of shape of NATO forces, 10s-100s of Western deaths/serious injuries, 1000s-10000s of Afghan security forces deaths, and 1000s-10000s of civilian deaths per year is not "low cost".
Prof Patrick Porter lectures on realism at UK Staff College... read his Twitter thread
@patrickporter76, he's knocking down the arguments against withdrawal like nine-pins.
Edit: I was just reflecting that the reported accommodation between the Taliban and China, not to interfere in suppression of the Uighur Muslims, is potentially a powerful counter-narrative for the West to use at home against the universalist claims of militant Islam and thereby to discredit jihadi recruiters. "Look, jihadis don't give a toss about their co-religionists, they're only interested in promoting their narrow political interests where they sense weakness".