It was a deeply emotional statement from the American president. 

He displayed an empathy that he is known for, but one which has not been on show over these past 10 days as he defended the chaotic withdrawal.

Reflecting on the death of the US troops, and speaking directly to a US audience, he drew on his own experiences – a son who has served on combat missions and who later died of brain cancer and a daughter who was killed in a car crash as a baby along with his first wife.

“We have some sense of the feeling…” he said, adding that the loss is like being “sucked into a black hole with no way out”.

But beyond the empathy he also attempted to demonstrate power, strength and steadfastness.

“We will not forgive. We will not forget. We will hunt you down and make you pay,” he said of the ISIS-K terrorists.

And he vowed to continue the evacuation mission.

“We must complete this mission and we will. We will not be deterred by terrorists. We will continue the evacuation.”

As commander-in-chief he has now pledged two such conflicting missions: to continue the evacuation, to get troops out, but also to hunt down the terrorists too.

This may require boots on the ground. It will certainly require intelligence that has evaporated with the US withdrawal and the abandonment and subsequent collapse of Afghan forces.

The cooperation of the Taliban will be critical and it’s intriguing that the generals admitted they are sharing some information with Taliban commanders. What a remarkable twist.

Remember, the Taliban and ISIS-K are enemies. But would the Taliban tolerate continued US operations? Would the American public tolerate it?

There were prickly moments in his news conference. He clashed with a Fox News reporter who pointedly but rightly put him on the spot – would he accept any responsibility for what has unfolded, he was asked.

He said the responsibility is his – “the buck stops with me” – but then repeated his charge that the chaos was the unravelling of a bad and binding deal he inherited between his predecessor Donald Trump and the Taliban in which the Americans pledged to withdraw if attacks on them stopped.

President Biden insisted that if he had ripped up the Trump-Taliban deal and left any troops in Afghanistan, the Taliban would have attacked and America would have been sucked back in.

Yet the cost of pulling out – and so quickly too – has been chaos, betrayal, abandonment and death within Afghanistan.

And beyond the country are the challenges of accommodating so many refugees. The numbers are manageable, but we saw how the Syria refugee crisis polarised politics across Europe.

There is an overarching predicament which President Biden will not confront. His central justification for pulling out – that Afghanistan was no longer a home for terrorists – has been proved so tragically wrong.

The country has been handed back to the Taliban, a group who remain close to al Qaeda and who can’t control their homegrown enemy, ISIS-K.

For now the terror threat does not present risks beyond Afghanistan in the way al Qaeda did 20 years ago.

But as former US Defence Secretary and former Director of the CIA, Leon Panetta said: “We’re going to have to go back in, to get ISIS.

“And we’ll probably have to go back in to get al Qaeda… We can leave the battlefield, but we can’t leave the war on terrorism.”