Just looking at the Abu Sayyaf material in these collections…

There’s some very useful material here, and some that is less so. The Christopher Collier essay on the ASG (in the CSIS collection) is excellent, and a welcome change from the many quite superficial treatments that have appeared recently. It’s refreshing to see open discussion of some of the oft-ignored aspects of this fight: the tendency for attribution of attacks to be driven as much by expedience as evidence; the reality that members Philippine security forces routinely sell arms and ammunition to insurgents, share ransom payments, and engage in other extracurricular business deals; the unreliability of ASG force estimates; the confusion between armed business disputes and insurgent/counterinsurgent encounters; the questionable level of connection between ASG and AQ in the last decade… and so on.

This excerpt deserves to be highlighted:

Seasoned anthropologist Thomas Kiefer has spent years studying the Tausug, the people of Jolo, and points out that the notion of a clearly bounded “group”—as in Abu Sayyaf Group—is virtually meaningless in Tausug society. Instead, Tausug political and military life is structured by temporary factional alliances, “overlapping and criss-crossing ties in which the same men may be torn apart and bound together in multiple ways at the same time.” So-called minimal alliance networks are centered on a charismatic leader and rarely number more than a score strong, with membership becoming vague at the edges as one network shades off into another. Such networks only come together as “medial” or “maximal” alliances of hundreds or even thousands of men if a third common enemy, shared among them, emerges. Because every man in every component minimal alliance follows only his own leader and is typically pursuing only individual advantage, not any generalized ideology, larger alliances of expediency are extremely unstable. Abu Sayyaf is just such a medial alliance. It has no firm boundaries—only leaders with followers who interact with other leaders with followers. Hence the difficulty in estimating Abu Sayyaf numbers.

Many armed encounters on Jolo and Basilan that are portrayed as clashes with Abu Sayyaf actually involve disputes over petty profiteering, such as the battle with Commander Nandi or guerrillas of the Misuari Breakaway Group of the MNLF (on Jolo) or MILF (on Basilan). In the face of a third common enemy, the AFP, the boundaries among these three theoretically discrete insurgent groups frequently become hazy, as leaders with personal ties form temporary medial alliances. It should be emphasized that these are personal alliances of convenience, more than organizational or ideological “links.”
The only thing I’d add to that is that wider alliances are driven not only by the emergence of a common enemy: the rapid expansion of the ASG in the early 00s (from several hundred to several thousand) was not an alliance against a common enemy or a sudden burst of enthusiasm for jihad but a reaction to the ASG’s success in attracting large ransom payments. The subsequent reversal of the ASG’s fortunes is widely attributed to US-backed Philippine military action. This was a factor, but there were other major contributing factors, notably the difficulty of integrating a large influx of nominally loyal and basically opportunistic “members” and often violent internal disputes over the distribution of ransom payments.

The ASG essays from the CTC and ASPI collections are much more conventional and much less interesting, apparently relying almost entirely on secondary and tertiary sources and often falling victim to the common tendency to treat the ASG as a discrete group with a coherent command structure and unifying ideogy. There are several serious stretches: recovering a pamphlet in an ASG camp does not justify the assumption that the contents of the pamphlet represent an organizational ideology. There are a few odd factual errors (Ramzi Yousef was arrested in Islamabad, not in Manila as the CTC essay states) and a generally unquestioned acceptance of the conventional account of ASG’s history, a history that deserves a good deal more questioning than it gets. It’s quite astonishing that until now reputable studies still describe Yousef’s Manila operation in ’94-’95 as an "Abu Sayyaf cell"… but given the general eagerness to characterize the ASG as a central link in the global jihad chain, I suppose that’s understandable.

The discussion of the Rajah Soleiman Movement (RSM) seems almost anachronistic: while the RSM did at one time appear to be emerging as a serious threat, it has been severely degraded and proved largely to be a one-man show, unable to recover from the arrest of leader Ahmed Santos. While the possible threat from small cells of militants operating on the fringes of the Luzon-based “balik-Islam” movement cannot be discounted, RSM as an organization seems to be in terminal decline.