Aman Abdurrahman is considered to be the de facto leader of all ISIS supporters in Indonesia. Photo: AFP / Bay Ismoyo

Terrorism specialists are beginning to change their tune over predictions that battle-hardened Indonesian jihadists returning from fighting for the Islamic State of Iraq and Syria (ISIS) could present a major security threat in the future. The reason: many may never come home. Now cut off from the Turkish border, militants holed up in the besieged Iraq city of Mosul and in ISIS’s Syrian headquarters in Raqqa may well be forced to fight to the death to defend the ever-shrinking caliphate.

Sealing off the two enclaves also means the number of Indonesians heading for the Middle East has dropped dramatically. Whether that will lead to a further uptick in terrorist activity in Indonesia itself remains to be seen. There still appears to be no shortage of local recruits, but Sidney Jones, director of the Jakarta-based Institute of Policy Analysis for Conflict (IPAC), says it now seems unlikely that many overseas Indonesian jihadis will escape the current offensives in Iraq and Syria.

An estimated 500 Indonesian nationals are believed to remain in the two countries, consisting of about 200 fighters and 300 dependents. More than 100 Indonesians had died in the conflict, as of October, but that number must be on the rise with recent intense fighting. Only two dozen militants had returned from the battlefield as of October, but they are not automatically detained and it is unclear what systems the National Anti-Terrorism Bureau have in place – if any – to monitor them. That may be rectified with new revisions to the 2003 Anti-Terrorism Bill which, if passed, will also allow police to detain suspects for up to six months and strip convicted terrorists of their passports.

In February 2016, in the first case of its kind, seven Indonesians were jailed for between three and five years for conspiring with ISIS and propagating extremist ideology, including four who travelled to Syria to undergo military training.

It is unclear to what extent the tightening of the vice around Mosul and Raqqa is affecting the ability of Indonesian leaders Bahrun Naim and Bachrumsyah Mennor Usman, who heads the Indonesian-Malaysian fighting unit known as Katibah Nusantara, to issue instructions to ISIS followers at home. On January 10, the US Treasury Department imposed financial sanctions against Bachrumsyah and the ISIS-affiliated ideologue Oman Rochmon – who is better known as Aman Abdurrahman and counted Naim among his prayer community before he left for Syria in early 2015 – identifying them as “Specially Designated Global Terrorists.”

The sanctions announcement said those designated are involved in “recruiting foreign terrorist fighters” and “spreading [ISIS] propaganda in Australia and Southeast Asia”, and that the measures aim to cut their finance channels. It also designated Jammah Ansharut Daulah (JAD), formed in 2015 and composed of almost two dozen extremist groups in Indonesia that have pledged allegiance to ISIS leader Abu Bakar al-Baghdadi, as a global terrorist organization.

Despite serving a nine-year term in the maximum-security Nusakambangan island prison since 2010, Abdurrahman is considered to be the de facto leader of all ISIS supporters in Indonesia, recruiting prospective militants and, according to the US Treasury, “most likely” still communicating with Naim and Bachrumsyah in Raqaa. The charismatic cleric, who has taken over the spiritual leadership position once occupied by the aging and likewise imprisoned Abu Bakar Ba’asyir, is suspected of ordering the bomb and gun attack in central Jakarta last January 14 which left four civilians and four terrorists dead.

Indonesian police guard the Jakarta Cathedral on December 24, 2016.
Photo: AFP / Bay Ismoyo

Two months after that attack, Backrumsyah is alleged to have transferred US$105,000 to the head of the Jakarta-based cell upended by the elite Detachment 88 counter-terrorism unit before it could carry out a series of Christmas-New Year bombings.Detachment 88 detained or killed at least 23 militants who planned attacks on the presidential palace, Jakarta’s Soekarno-Hatta international airport, police stations, churches and even the Myanmar Embassy, the target of protests over the treatment of the Rohingya Muslim minority in that country.

Among those arrested was overseas domestic worker Dian Yulia Novi, who would have become Indonesia’s first female suicide bomber if she had not been stopped from blowing herself up outside the palace on a car-free Sunday morning when hundreds of pedestrians are usually out on the streets. The day before, agents watched her handlers reconnoitre the path the 27-year-old maid would have taken, lugging a pressure-cooker bomb concealed in a backpack the short distance from the Istiqlal Mosque and timing her arrival just as the guard was changing.

Terrorism expert Jones has long warned that female Indonesian extremists want a greater role because of their admiration for women carrying out terrorist attacks in Iraq, Syria and Jordan whom they have read about on the Internet. Although ISIS issued a directive at one point that women should not be used in actual operations, it now appears to have been relaxed. Their involvement would be a worrying development in Indonesia because they will always attract less suspicion.

Although ISIS issued a directive at one point that women should not be used in actual operations, it now appears to have been relaxed. Their involvement would be a worrying development in Indonesia because they will always attract less suspicion

Eight women are among the 120 terrorist suspects, most of them ISIS supporters, who were arrested between January and November last year, including three female combatants captured during operations in the jungles of Central Sulawesi against the country’s only known Islamic insurgency. Novi is the second wife of Internet salesman Nur Solihan, the leader of the terrorist cell uncovered in the western Java suburb of Bekasi on December 10. Over the next fortnight, police rounded up another 18 suspects – including two women – and killed three militants in a December 21 gunfight in nearby Tangerang.

Ordnance experts detonated 14 pressure-cooker acetone bombs after that raid, an indication of the advanced level of planning for an end-of-year bombing campaign that would have claimed dozens of lives. Police say Solihan was one of the most skilled bomb-makers they had captured in recent years, claiming he had access to three times more explosive than that used in the devastating 2002 Bali nightclub bombing which killed 202 people, mostly foreigners.

US treasury officials claim Bahrumsyah also transferred funds directly to the terrorist group Mujahidin Indonesia Timur (MIT), whose long-sought leader, Joko Santoso, was killed in his Central Sulawesi stamping ground only four months later. How long he and Naim can go on funding and directing operations from afar, however, may depend more on what happens on the battlefields of the Middle East than on any purse-string sanctions Washington aims to impose.

John McBeth, a former correspondent with the Far Eastern Economic Review, is a Jakarta-based columnist with over 45 years’ experience covering Southeast Asia.