On 10 December, Philippine President Rodrigo Duterte announced the end of martial law in Mindanao after opting against an extension, on the advice of military and police chiefs. The emergency measure, which was first imposed in the restive region in response to an ISIS-led siege of Marawi city in May 2017, had previously been extended three times and is now set to expire on 31 December. Two years after ISIS were defeated in Marawi, the jihadist threat has been reduced to a more manageable scale.

The ISIS-affiliated groups which led the siege have been pushed back and many of their leaders killed, leading Defence Secretary Delfin Lorenzana to declare his preference for lifting martial law entirely in November. Armed Forces of the Philippines (AFP) and Philippine National Police (PNP) chiefs initially suggested extending the measure only in ‘selective areas’ where extremist groups still operate. The provinces of Maguindanao and Sulu have both experienced attacks by ISIS-affiliated groups this year.

With martial law lifted, what level of threat do ISIS’ surviving local affiliates represent in Mindanao? And despite ISIS’ declining global influence, after territorial losses in the Middle East and the death of its leader Abu Bakr al-Baghdadi in a US raid in Syria, could its followers in the Philippines rebound?

ISIS remnants in Mindanao

The Maute Group, accused of planning the assault on Marawi in an attempt to carve out a Southeast Asian ISIS caliphate, are severely depleted after AFP operations in Lanao del Norte and Lanao del Sur. While the group was 1,000-strong ahead of the siege, it is now thought to have fewer than 25 active members. Its founders, brothers Abdullah and Omar Maute, were killed during the final gun battles in Marawi in October 2017; while its new leader, Abu Dar, was shot dead during a military operation in Tubaran on 14 March, leaving the Mautes without a main figurehead. After Abu Dar’s killing, the AFP said the Mautes were no longer capable of launching a Marawi-style raid, yet military spokesman Col. Romeo Brawner warned that the group was still trying to recruit and remains a national security risk.

The Bangsamoro Islamic Freedom Fighters (BIFF), which played a minor supporting role in the Marawi siege, emerged relatively unscathed and posed a larger threat in its aftermath. In 2018, they regularly fought government troops and carried-out a string of bombings, maiming civilians in restaurants and shopping malls, in the provinces of Maguindanao, North Cotabato and Sultan Kudarat. However, AFP airstrikes and ground operations targeting BIFF hideouts in the rural Liguasan Marsh area of central Maguindanao have dented the group’s capabilities in 2019. In April, regional military commander Maj. Gen. Cirilito Sobejana said the three BIFF factions – the most powerful of which is led by ISIS-affiliated militant Abu Toraife – had been forced into a tactical alliance and resorted to guerrilla-style tactics to survive while under growing pressure. In recent months, the group’s remaining fighters have lain low.

A smaller ISIS-aligned group, Ansar Khalifah Philippines (AKP), also remains active further south, in the provinces of Sarangani and South Cotabato. However, since its leader Mohammad Jaafar Maguid was killed in a firefight with police in 2017, AKP has been regarded by the authorities as more of a criminal nuisance than a transnational terror threat, having engaged only in a series of small-scale gun battles.

The threat from Abu Sayyaf

The Philippines oldest known jihadi group, Abu Sayyaf, which was formed in the early-1990s, currently represent the gravest threat of all Mindanao’s ISIS affiliates. After playing a leading role in the Marawi siege alongside the Mautes, Abu Sayyaf retreated from mainland Mindanao to their former maritime hideouts on the island provinces of Basilan, Sulu and Tawi-Tawi. After regrouping and replenishing its ranks, Abu Sayyaf has rebounded in 2019. The most extreme faction, led by ISIS supporter Hatib Hajan Sawadjaan, has perpetrated a wave of high-profile suicide bombings in Sulu this year. On 27 January, two militants detonated themselves inside a crowded cathedral in Jolo, leaving 22 worshippers dead and 81 wounded. A second double suicide attack killed eight people at a military base in Indanan on 28 June, while a fifth bomber blew themselves up at an AFP camp in the same town on 8 September.

The bombings were all claimed by ISIS via official statements. Several of the suspected bombers were revealed to be Indonesian and Moroccan nationals, adding to concerns that Abu Sayyaf is harbouring foreign fighters trained in bomb-making and willing to volunteer themselves for suicide missions. Back in July, Maj. Gen. Sobejana had warned that seven foreign terrorists were training Filipino militants in IED construction while another 42 suspected foreign fighters were being monitored by the authorities. He said many of these suspects were likely ‘embedded’ with Abu Sayyaf and the BIFF. On 5 November, government soldiers shot dead two Egyptian militants at a checkpoint in Jolo, confirming these fears.

Abu Sayyaf has around 400 fighters and continues to fight the army under the command of Sawadjaan in Sulu, while another ISIS-linked faction led by Furuji Indama remains active in Basilan. Smaller cells are active in the Tawi-Tawi islands, while Abu Sayyaf activity has been reported in Malaysia’s eastern state of Sabah and along the coast of mainland Mindanao’s Zamboanga peninsula. Abu Sayyaf is also notorious for launching piracy attacks and kidnappings-at-sea, several of which have occurred in 2019.

Guarding against an ISIS resurgence

Although degraded post-Marawi, and contained to the remote southwest of the country, ISIS-aligned groups are still active and intent on forging a regional caliphate centred on the southern Philippines.

There is growing concern that the BIFF and Mautes may look to replenish their ranks by targeting the 66,000 residents still displaced from Marawi city, more than two years since the end of the siege. The government has been criticized by its opponents for the slow pace of rehabilitation, with the central Banggolo district still in ruin and needing to be cleared of unexploded ordnance before building work can begin. It is feared that young men with limited economic opportunities and their livelihoods placed on hold due to the ISIS-led siege, may ironically become prime targets for recruitment by jihadi groups. Tensions are rising, with the government’s 2021 target for rebuilding the city unlikely to be achieved.

An extension to martial law in Abu Sayyaf and BIFF strongholds would have helped the AFP maintain pressure on ISIS remnants; but the military and intelligence agencies will maintain vigilance regardless. The AFP will likely continue launching airstrikes and undertaking ground offensives in the ISIS hotspots of Sulu and Maguindanao; while also holding regular trilateral naval patrols alongside Indonesian and Malaysian forces in the Sulu Sea, to deter kidnappings and prevent the movement of foreign fighters. Guarding against the transition of Abu Sayyaf to mainland Mindanao is crucial in preventing a repeat of Marawi, when the Philippines’ four ISIS-linked groups were able to join forces to take-over the city.

Hopes are also invested in a peace deal signed between the government and an older, more moderate Muslim rebel group, the Moro Islamic Liberation Front (MILF). The accord, ratified in a referendum in western Mindanao earlier this year, will see former rebels govern a new Muslim autonomous region, encompassing the core territories where ISIS-linked groups remain active. If the deal brings economic development and enhances livelihoods, then ISIS – known to prey upon unstable and poverty-stricken regions to reinvigorate itself – may be denied a climate conducive to its resurgence in the Philippines.

An earlier version of this article, written before it was announced that martial law would not be extended beyond December 2019, is published on Geopolitical Monitor.