There is no doubt President Donald Trump inherited a bad hand in Afghanistan. The longest war in US history is probably unwinnable. Russian, and before that British, military history said as much even before George W Bush invaded 16 years ago in the wake of the September 11 terrorist attacks on US soil.

And yet, predictably from the vantage point of the Oval office, Mr Trump has found the consequences of turning tail too grave to contemplate. To do so, as he said in a speech outlining his approach to Afghanistan on Monday, would “create a vacuum that terrorists, including Isis and al-Qaeda, would instantly fill”. It would be to repeat the mistake that the Obama administration made when it withdrew from Iraq prematurely in 2011, allowing Isis to capture territory that US and Iraqi soldiers had lost much blood to gain. From a domestic political perspective that prospect would be as untenable as launching another wholehearted surge.

So, having pledged on the campaign trail to end the war in Afghanistan and eschew such foreign entanglements in future, Mr Trump has heeded his generals’ advice and performed an about turn. He did so with harsh warnings for Pakistan, which he accused of harbouring terrorists, conditional love for Afghanistan’s embattled government, and a vague plan to reinforce the 10,000 or so mostly special forces now on active duty to train and assist the Afghan army.