Announcing the withdrawal of US troops from Afghanistan this week, two decades after they first arrived in the country, Joe Biden said it was “time to end America’s longest war. It’s time for America’s troops to come home.”

The short address was frank: “We delivered justice to Bin Laden a decade ago and we’ve stayed in Afghanistan a decade since. Since then, our reasons for remaining in Afghanistan are becoming increasingly unclear,” he said. All but acknowledging the consequences of the move, Biden argued that America could not “continue the cycle or extending or expanding our military presence in Afghanistan hoping to create ideal conditions for a withdraw.”

Biden has been sceptical of America’s ongoing involvement for at least a decade. In his memoir, Barack Obama writes that his Vice-President saw Afghanistan as a “dangerous quagmire”. That dovishness is made abundantly clear in a 2010 exchange between Biden and Richard Holbrooke recounted in Our Man, George Packer’s 2019 biography of Holbrooke. The then Special Envoy for Afghanistan and the then Vice-President are discussing America’s presence in the country:

When I mentioned the women’s issue, Biden erupted. Almost rising from his chair, he said “I am not sending my boy back there to risk his life on behalf of women’s rights, it just won’t work, that’s not what they’re there for.”… I tried to outline the position Hillary and I had taken. He thought it was bullshit… Joe took the position, plain and simple, that we have to get out of Afghanistan… I thought we had a certain obligation to the people who had trusted us. He said, “Fuck that, we don’t have to worry about that.”

Biden’s decision as president should therefore come as no surprise. In setting the withdrawal deadline of September 11 (a bafflingly crass choice of date), he has formally turned the page on an era of US foreign policy.

Given the significance of the moment, the response in Washington has been revealingly muted. A handful of Democrats criticised the move and Republican Senate leader Mitch McConnell characterised Biden’s decision as a “grave mistake” and “retreat in the face of an enemy”.  But after four years of a Republican president who railed against “forever wars”, and a GOP base far more sceptical of foreign intervention than it once was, the sting has gone from such attacks.

That doesn’t mean there aren’t strong arguments against withdrawal. An intelligence report released this week painted a bleak picture of Afghanistan’s future. The Afghan government, the report said, “will struggle to hold the Taliban at bay if the coalition withdraws support.”

If the US can spare 500 more troops in Germany to counter Russia, can it not justify a 3,500-troop presence in Afghanistan for the more immediate task of keeping the Taliban out of power? Strip away talk of “forever wars” and “acting as the world’s policeman” and that becomes a question with a less obvious answer. Perhaps the price of a continued presence in Afghanistan really does outweigh the upside of staying, but America’s decision does not appear to be the result of a hard-nosed cost-benefit analysis.

The Afghanistan withdrawal is only the latest piece of evidence that Biden, who promised a return to the pre-Trump status quo, is delivering something different. On foreign policy, as with economic policy, the president is making a clean break with Obama-era Democratic politics. In decision after decision, the Biden administration delivers a sharp rebuke of the pre-Trump conventional wisdom.

In Afghanistan, that conventional wisdom dictated that protecting American interests necessitated keeping the Taliban out of government. The logic of the withdrawal suggests that Biden thinks otherwise. Let’s hope he is right.