May 16 (UPI) -- It was no coincidence that Sunday's suicide attacks on three Catholic churches in Indonesia came as Muslims began the holy month of Ramadan.
For the observant, this is a time of charity, introspection, renewal and closeness to God. For Islamic State, however, Ramadan has become a strategic time in which to strike, inspired by the Battle of Badr in the year 624, when the Prophet Muhammad and his army defeated a vastly superior force and laid the foundation for the growth of Islam.
Around the time of Ramadan last year, the Islamic State claimed over 300 separate attacks worldwide.
The gruesome church attack on Sunday, which involved using children as suicide bombers and left 13 people dead and more than 40 injured, also follows another pattern -- an uptick of violence linked to the terrorist group in Southeast Asia.
As Islamic State has lost vast swaths of territory it once controlled in Iraq and Syria, it has actively sought to mobilize support with jihadist groups in other countries such as Libya, Yemen, Nigeria and Bangladesh.
Southeast Asia, particularly the Philippines and Indonesia, was also identified as a core target of the group in an article in the Islamic State magazine Rumiyah in 2017. And in a worrying sign for the region, the number of attacks has been on the rise, driven in part by the return of fighters from the front lines of Islamic State's battles in the Middle East.
Returning foreign fighters
Conservative estimates suggest more than 1,000 fighters have traveled to the Middle East from Southeast Asia to join the Islamic State over the past five years. Of these, 700 are estimated to have come from Indonesia, about half of whom were male fighters, the other half women and children joining their husbands. Another 75 Indonesian fighters were deported from Turkey before they could travel to Syria.
Considering Indonesia is home to 225 million Muslims, the number of Indonesians who fought in Iraq and Syria is remarkably low. (Australia, with just over 604,000 Muslims, has seen more than 100 of its citizens join the fight, with up to 87 deaths at last count).
Journalists and scholars have argued that Indonesia's pluralism has played a significant role in limiting the outflow of fighters to the Middle East.
However, as has been made painfully clear in attacks like the one on the Bataclan theater in Paris in 2015, the actions of just a handful of trained Islamic State fighters can have a devastating impact -- both in terms of casualties and the wider political fallout.
Though Indonesian intelligence forces are well-trained and have been working with countries like Australia to improve the sharing of information across borders, there are no laws prohibiting Indonesians from travelling overseas to join the Islamic State. Nor is it illegal to express support for the group.
Adding to the problem is the fact that Indonesia's borders are exceptionally porous, making it almost impossible to prevent returning fighters from slipping back into the country unnoticed.
The threat from within
It was initially reported by media outlets that the family responsible for the church bombings on Sunday had also fought in Syria, a claim that has now been retracted.
But they were linked with Jemaah Ansharut Daulah, an umbrella organization consisting of up to two dozen affiliated militant groups. The leader of JAD, Aman Abdurrahman, is being held at the prison that was the scene of deadly riots by Islamic State followers a week ago and led to the deaths of several prison guards.
The militant groups operating within the JAD umbrella are relatively autonomous and don't have a great deal of interaction with one another. However, it is almost certain, though difficult to substantiate, that fighters returning from Iraq and Syria have joined up with a number of them, bringing their battlefield experience and militant skill sets with them.
JAD has also pledged its support to the Islamic State. This pledge of allegiance, or bayat, to Islamic State leader Abu Bakr Al-Baghdadi requires followers to follow Al-Baghdadi's orders but gives them autonomy to conduct terrorist operations against the state, rejectionists and apostates.
The Islamic State continues to enjoy a sizable level of support among everyday Indonesians, as well. A Pew Research study found that 4 percent of Indonesians have a favorable opinion of the group, which may seem small, but in numerical terms, constitutes over 9 million people. As Indonesian society has slowly become more conservative in recent years, this support is sure to grow.
The Indonesian government faces a significant challenge overcoming the simultaneous problems of returning foreign fighters and home-grown violent extremism.
But no nation can battle terrorism alone. Though Australia and Indonesia have been working well together on counterterrorism initiatives, a senior Australian government official told The Australian on Monday that Canberra would "double down" on its cooperation with Jakarta to tackle the issue of returning foreign fighters.