Raqqa, Syria: A soldier of the Syrian Democratic Forces (SDF) looking through a hole in a wall while battles against the Islamic State (IS) terror militia continue, 11 August 2017. Morukc Umnaber/PA Images. All rights reserved.Raqqa, 25 August 2017

Thank you for your letter. It has only just arrived as the internet connection has been sporadic, and I hope this reply reaches you soon. Thank you also for asking after my brother. Again, connections are difficult but when our associates in the Philippines asked for advice on their unexpected gains in Marawi he was immediately sent to help out.

That was always expected to be a brief operation and I understand that the leadership there was really surprised that the Filipino army offered such little resistance. Given my brother’s huge experience in Iraq, Syria, Bangladesh, and especially Libya, I would not be at all surprised if he was of great value in extending the operation. However I understand that he is now moving on to Afghanistan where there are so many opportunities and so much work to do.

Although the leadership in the Philippines only has loose connections with us here, we have watched closely what happened and I hear that our strategy people are very happy with the result. When the operation started in late May the aim was simply an “in and out” incursion to demonstrate that the movement could take over a city if it so chose.

That it has lasted so long in spite of considerable American military assistance has been a joy to watch. Even better has been the way that government forces have been reduced to using air attacks and artillery bombardment in their chaotic attempts to retake control of Marawi. The result is scores of civilians killed, swathes of the city wrecked, and a legacy of bitterness against the government. The operation is now coming to an end but our associates are very pleased. Just when the organs of the far enemy are declaring us defeated, this is what we do!

Just when the organs of the far enemy are declaring us defeated, this is what we do!

I do sense from your letter, though, that you want me to try and explain why I still feel so optimistic about the future of our mission. Let me start by reminding you of some of the things I said in my two previous letters, on 17 March and 14 May this year. In March, it was already clear that what was happening in Mosul would be greatly to our advantage in two respects: our progressive crippling of the Iraqi special forces (even before then their so-called “golden division” was looking decidedly rusty) and the loss of civilian life as the crusaders increased their aerial bombardment.

In May, I updated you on these aspects and outlined why I still felt positive. You'll remember how I ended it: "That, in short, dear friend is why I write so optimistically. Yes, I may be killed in a drone strike tomorrow and go with joy to what follows. It will perhaps be a relief and a culmination of my life, but the curious thing is that one part of me wants to carry on living just to witness the extent of their failures in the years to come. Do try to understand that, because I say it too you in all sincerity.”

So let me define where we now stand, with three key points. First, Mosul has now largely fallen to the Iraqis, but even they are admitting the losses in their special forces (at least 40% killed or seriously injured, and training replacements will taking a year or more). Since these are the only forces that the Baghdad cabal can rely on, that alone will add to the endemic insecurity throughout the country.

Second, the sheer destruction meted out in Mosul is compared even by western journalists to Stalingrad. You remind me once again of the repeated anger of your friends in Britain about the extent of our brutality, both in Iraq and in our attacks across Europe.

Perhaps you could explain to them that the air assault by the Americans and their allies has now been going on for three years with air raids and drone attacks day and night. Even the Pentagon now admits that the war has killed 60,000 of us. What they will not admit is that this includes many thousands of women and children. Every one of us has lost close family members and friends, so is it any surprise how we act when we get the opportunity?

Third, the Iraqis are having increasingly to rely on Shi’a militias that are consistently alienating themselves from our Sunni people. Furthermore, many of them are officered and funded by the Iranians, with the result that support for our cause from Saudi and other sources is starting to increase.

Look at it this way. When Bush and his allies terminated the Saddam Hussein regime back in 2003, they expected a subservient post-war Iraq that would be thoroughly pro-western and would help constrain Iran, especially as the Americans then expected a similar outcome in Afghanistan. Iran would thus be facing the Americans and their allies to their west and east, with the reinforced United States navy’s fifth fleet controlling the Gulf and the Arabian Sea. From Washington’s perspective, there would be no further problem with Iran. "The road to Tehran runs through Baghdad”, the beltway saying of 2002 had it.

"The road to Tehran runs through Baghdad”, the beltway saying of 2002 had it.

Instead, Iran has massively increased its influence in Iraq and has made impressive inroads into north-west Afghanistan. In the Gulf itself, the Saudis and other illegitimate regimes are scared rigid by the unfolding of the “Shi'a crescent” from the Mediterranean to the Arabian Sea. They will now do all they can to aid any movement that can help counter that. We expect to gain hugely as we transit to a guerrilla war in Iraq and Syria.

Then, look at Afghanistan and Trump’s newly announced policy which amounts to more of the same. The Americans have about 9,000 troops there and plan to expand this to perhaps 14,000. Here it's useful to recall that when Obama finally decided what to do about Afghanistan in 2010, he added 30,000 more troops to the then force of 70,000. The aim was not to defeat the Taliban but force them to the negotiating table from a position of weakness. That failed abysmally, yet Trump and his generals believe they can do it now with minimal forces.

I won’t bother to remind you of all the developments in Mali and other parts of the Sahel, or of the shock to Spain's security people last week when they discovered that a substantial active service unit was operating in Catalonia, under their noses. It was one of many now operating across Europe. They are further aided by determined fighters returning from Iraq and Syria to their own countries.

Even so, you might still ask: “what about the caliphate, has not the centrepiece of the mission gone?” But you have to understand that as soon as the intense crusader air assault started three years ago, our leaders quickly saw that the caliphate would evolve from being a physical actuality to a powerful symbol of what can be achieved, and against the combined forces of the most powerful military states on earth. They can fly their drones and drop their guns and missiles with impunity – yet we survive!

Remember that three years ago the Pentagon estimated that we had 25,000-30,000 fighters supporting us but now claim to have killed at least twice that number in their air assault. They simply have no understanding that you cannot defeat an idea by bombing it.

What you have to grasp is that we have already moved on beyond the caliphate and that it is now the symbol that counts. It will surely come again because of one more element that the crusaders and Zionists cannot understand. Namely, we are not engaged in this mission for ten, twenty, fifty, or even a hundred years, we are in it for eternity.