I feel this has become a game changer the world will not forget if called upon again.
Easy, I am talking in the relative short term, not long term.
Trump promised to 'end the forever wars' before he was even elected in 2016. His Doha agreement with the Taliban promised complete US withdrawal by 31 May 2021. Biden confirmed in April that the withdrawal would go ahead, with a new deadline for logistic reasons but still in time for the 9/11 anniversary. How much more warning did anyone need? The simple fact is that the UK and others dragged our feet because our policy elites didn't understand how precarious the Afghan house of cards was, and in their permanent state of optimism thought they would be able to pressure Biden into changing his mind. Which is a very arrogant stance to take when it's considered that 1) we drew down our combat missions years ago, 2) it would be US soldiers bearing the brunt of renewed Taliban attacks on NATO troops, and 3) we all drastically underspend on defence by comparison to the US. Why should the US have patience for those kind of games when it's facing the expiry of a ceasefire it negotiated 18 months ago, and has already extended once?
The UK meets their expenditure on defence commitment, I realise that it is US troops degending Kabul airport on the whole, but then the struggle to evacuate only came about because of the idiotic decision to depart when they have, so is a knock on effect of that policy, do we just write off those citizens because of that?