Colin Brazier: Afghanistan may well be the world’s most pressing humanitarian crisis. Lift your sights Boris Johnson

The first time I went to Afghanistan the Taliban were still in charge. It was a basket-case, lawless, anarchic, dangerous. Just getting into the country involved a nightmare journey from Tajikistan in an old Russian jeep, fording rivers and navigating mountain passes.

The next time I went, the Taliban had largely been vanquished and things couldn’t have been more different. A comfortable flight into Bagram and a US army base where you could buy burgers and fries.

But, if things keep going as they are, getting into Afghanistan will be a deadly enterprise again.

To which you might say: why would I want to get into Afghanistan? Well, you might not, but the people you entrust to keep us all safe might need to. And my point is, that it’s always harder to fight your way in, than it is to hold what you have; always bloodier to attack than it is defend.

Let’s take the worse case scenario which, if you look back at Afghanistan’s history, is the obvious place to start. In the Spring, Joe Biden announced US forces were leaving. They’d be gone before the 20th anniversary of the attacks on September 11, 2001, which were planned in Afghanistan.

Reluctantly, Britain fell into line and has pulled out all but a handful of Special Forces and embassy guards. Large swathes of Helmand Province, where more than 400 British servicemen died, are now being re-occupied by a resurgent Taliban.

Last month on GB News, the former head of the British Army, Lord Dannatt, told me the Taliban had finally won their war of strategic patience. How does any of this affect your life? Well, in two ways. First, twenty years of Western involvement has given millions of Afghans a taste for freedom. If and when the Taliban take over, banning music, dancing, football, kite flying and education for girls, many Afghans will head West, fearing for their lives and future.

Already there are reports of hundreds of Afghans in Turkey. A repeat of the migrant exodus seen in Syria in 2015 is not impossible. There are probably at least 100,000 Afghans living in Britain, and the communities they form would be a magnet for newcomers.The second way events 4000 miles away wash up on your doorstep is for the same reason it mattered the first time around.

Afghanistan will become a playground for people who want to kill you. I know there are those who say Islamic State and Al Qaeda have lots of other places in the world where they can ponder your annihilation, Africa most obviously. But Afghanistan has a special place in their twisted hearts.

If they can turn it into a failed state again, or better still for them, an Islamic State, they will send out a message to the world that the West is fading and they are rising. All this may, on the balance of probabilities, will happen. Biden has made a catastrophic blunder. But are we so powerless that we have to withdraw too, and watch Afghanistan burn?

And the sacrifices of 454 British personnel count for naught? In his most famous wartime speech Winston Churchill promised that Britain would fight on “if necessary alone”. And there are voices which are beginning to advance the same argument, most notably two former Defence ministers Johnny Mercer and Tobias Ellwood.

Mercer, who served three tours of Afghanistan, asked: “Are we really so tied to the Americans that we cannot do anything ourselves or with other NATO partners?”

While Ellwood asserted this: “We are capable of acting without the Americans and it’s time to prove it.”

The naysayers will claim this is so much war-mongering, not just jingoistic, but expensive. Our exploits in Afghanistan cost, not just lives, but £22 billion.

But two years of our international development budget would cover that cost with change left to spare. In weeks, Afghanistan may well be the world’s most pressing humanitarian crisis. Lift your sights Boris Johnson.

If necessary, use our foreign aid budget. Either way, use our expertise. Most of all, use our aircraft and ground forces. Revivify Britain’s martial self-confidence, persuade other NATO partners to come back in, deny the Taliban a victory for nihilism. Save millions of girls from a future of illiteracy and medievalism and save Europe from a new influx of refugees.