I've come across several thought-provoking analyses of what's happening in the fundamentalist Islamic terrorist world at the moment, and the current tactics being implemented in Syria.
First, War On The Rocks reports on 'The Islamic State vs. al-Qaeda: The War within the Jihadist Movement'. Here's a brief excerpt from a long and detailed article.
The post-Arab Spring period has seen extraordinary growth in the global jihadist movement. In addition to the Islamic State seizing a vast swathe of territory spanning Syria and Iraq and al-Qaeda establishing itself as a potent military force in the Syrian civil war, instability and unfulfilled expectations in numerous countries — including Egypt, Libya, Mali, Tunisia, and Yemen — have presented jihadists with unprecedented opportunities.
But even as the jihadist movement experiences rapid growth, it has also endured unprecedented internal turmoil. The Islamic State’s emergence marks the first time that leadership over the global jihadist movement has been seriously contested. Since that group’s expulsion from the al-Qaeda network in February 2014, a fierce competition between the Islamic State and al-Qaeda has defined the militant landscape. The United States has an opportunity to exploit and aggravate fissures within the jihadist community, but to do so successfully, it is essential to understand the differences in the modus operandi of these two rival jihadist groups.
Two Models of Revolutionary Warfare
Though al-Qaeda and the Islamic State share the same ultimate goal — establishing a global caliphate ruled by an austere version of sharia (Islamic law) — each group maintains a distinct approach to revolutionary warfare. Al-Qaeda has come to favor covert expansion, unacknowledged affiliates, and a relatively quiet organizational strategy designed to carefully build a larger base of support before engaging in open warfare with its foes. By contrast, the Islamic State believes that the time for a broader military confrontation has already arrived, and has loudly disseminated its propaganda to rally as many soldiers as possible to its cause. The group combines shocking violence with an effective propaganda apparatus in an effort to quickly build its base of support.
The Maoist and focoist schools of revolutionary thought provide a useful framework for understanding these groups’ differing strategies. Al-Qaeda exhibits a revolutionary strategy that is both implicitly and explicitly based on the works of Mao Tse-tung, while the Islamic State’s approach is more consonant with the focoist writings of Ernesto “Che” Guevara and Régis Debray.
There's much more at the link, including a detailed analysis of how these different approaches are playing out in practice.
Next, from the Foreign Military Studies Office of the US Army comes a very interesting article titled 'Combat in Cities: The Chechen Experience in Syria' (link is to an Adobe Acrobat document in .PDF format). It analyzes how Chechen Muslim fundamentalist terrorists went to Syria to support like-minded terror movements there, and how they took with them the lessons they learned in urban combat against Russian forces during the 1990's and 2000's. Here's a brief excerpt from a long and detailed article.
Currently, at least three Chechen “battalions” are engaged in fighting against the Syrian government, and some individual combatants are part of ISIL (Islamic State of Iraq and the Levant). These Chechen are sharing their combat-in-cities tactics, techniques, and procedures (TTPs) with other rebel groups trying to overthrow the Syrian and Iraqi governments.
. . .
... some of the most notable Chechens fighting in Syria and Iraq are not technically Chechen but Kists from the Republic of Georgia’s Pankisi Valley and Gorge. The Kists are a close relation to the Chechens and are often referred to as cousins. During the wars with Russia, the Pankisi Valley was a refugee destination but also a sanctuary or “R&R” location for Chechen combatants taking a break from the fight up north ... In addition, it was a way station for foreign fighters seeking to get to Chechnya. The fact that important Chechen combatants fighting in Syria and Iraq are not even Chechen but rather Kist attests to the spread of Chechen influence and also TTPs beyond Chechnya, beyond the Caucasus, and now into the Middle East.
. . .
The Chechens are not present in overwhelming numbers anywhere in Syria or Iraq, nor in ISIL. Nor are all Chechen combatants in Syria former combatants in Chechnya, but they are a product of the Chechen diaspora or have taken the moniker of “Chechen” — like Salah al-Din Shishani and Umar Shishani. However, they have “street cred” and a reputation to maintain. They represent a significant fighting capability with a strong track record in a combat force that is learning to fight by doing it and then taking what has worked since the initial street fights of Grozny in December and January 1994 to advance their ability in the current struggle for Syria and Iraq.
Again, there's much more at the link, including considerable detail about Chechen 'doctrine' in how to conduct urban guerrilla operations. Speaking from my own experience in urban security operations (in a different part of the world, to be sure, and under rather different circumstances), the points made by the article ring true.
A third, older article is interesting because it shows how Israel re-learned the lessons of the Battle of Stalingrad and other urban fights during the Second World War. Those same lessons were also learned in Chechnya by both sides of the conflict, and are now being applied in Syria by all sides as well. In his essay 'Lethal Theory' (link is to an Adobe Acrobat document in .PDF format), Eyal Weizman analyzes the tactics used by the Israeli Defense Force in its fight in the city of Nablus in 2002. Despite his left-wing, anti-war bias, his article is very interesting from a tactical point of view. Here's a very brief excerpt, in which he quotes (in italics) Aviv Kokhavi, who at the time was the Commanding Officer of the Paratrooper Brigade.
This space that you look at, this room that you look at, is nothing but your interpretation of it. Now, you can stretch the boundaries of your interpretation, but not in an unlimited fashion, after all, it must be bound by physics, as it contains buildings and alleys. The question is, how do you interpret the alley? Do you interpret the alley as a place, like every architect and every town planner does, to walk through, or do you interpret the alley as a place forbidden to walk through? This depends only on interpretation. We interpreted the alley as a place forbidden to walk through, and the door as a place forbidden to pass through, and the window as a place forbidden to look through, because a weapon awaits us in the alley, and a booby trap awaits us behind the doors. This is because the enemy interprets space in a traditional, classical manner, and I do not want to obey this interpretation and fall into his traps. Not only do I not want to fall into his traps, I want to surprise him! This is the essence of war. I need to win. I need to emerge from an unexpected place. And this is what we tried to do.
This is why we opted for the methodology of moving through walls ... Like a worm that eats its way forward, emerging at points and then disappearing. We were thus moving from the interior of homes to their exterior in a surprising manner and in places we were not expected, arriving from behind and hitting the enemy that awaited us behind a corner ... Because it was the first time that this methodology was tested [at such a scale], during the operation itself we were learning how to adjust ourselves to the relevant urban space, and similarly, how to adjust the relevant urban space to our needs ... We took this microtactical practice [of moving through walls] and turned it into a method, and thanks to this method, we were able to interpret the whole space differently! ... I said to my troops, "Friends! This is not a matter of your choice! There is no other way of moving! If until now you were used to moving along roads and sidewalks, forget it! From now on we all walk through walls!"
. . .
A survey conducted after the battle by the Palestinian architect Nurhan Abujidi showed that more than half of the buildings in the old city center of Nablus had routes forced through them, resulting in anywhere from one to eight openings in their walls, floors, or ceilings, which created several haphazard crossroutes that she could not understand as describing simple linear progression, and which indicated to her a very chaotic maneuver without a clear direction.
For anyone who might imagine that moving through walls is a relatively "gentle" form of warfare, the following is a description of the sequence of the events: Soldiers assemble behind a wall. Using explosives or a large hammer, they break a hole large enough to pass through. Their charge through the wall is sometimes preceded by stun grenades or a few random shots into what is most often a private living room occupied by unsuspecting civilians. When the soldiers have passed through the party wall, the occupants are assembled and locked inside one of the rooms, where they are made to remain - sometimes for several days - until the operation is concluded, often without water, toilet, food, or medicine.
More at the link.
A fourth article, 'Nakatomi Space' at BldgBlog, analyzes Weizman's report in terms of the movie 'Die Hard'. It's an interesting alternate perspective, and I found it worthwhile.
It's reported that all sides in the Syrian conflict are now using similar urban warfare techniques (although they usually kill anyone they come across, civilian or fighter, rather than hold them captive). This has implications for counter-terrorism training and operations in the USA as well. Are our security forces (including local and regional police forces) trained to expect terrorists to move through buildings in this way? And are they trained to avoid doors, windows, etc. themselves? After all, terrorists who've experienced this sort of urban combat will be trying to kill them as they use conventional openings. It's a serious risk.
I recommend all four articles mentioned above. They contain a lot of useful food for thought.