The threat of South-east Asia turning into the next battlefield for the Islamic State in Iraq and Syria (ISIS) looms large, with the militant group expected to cede even more territory in the Middle East to coalition forces next year.
The exodus ofabout 1,000 Indonesian, Malaysian, Filipino and even Singaporean fighters from places such as Iraq, Libya or Syria will up the ante in the war on terror.
"We expect the returning fighters from Indonesia, Malaysia, the Philippines and a few from Singapore who are now in Iraq and Syria will likely return to continue their violent plots at home," Singapore Defence Minister Ng Eng Hen said recently.
Experts said the influence of these South-east Asian militants on their counterparts at home is already changing the way the battle is being fought by counter-terrorism agencies in this part of the world.
"What is happening now is not home-grown terrorism... (but) a global terrorist network," said Indonesian police chief Tito Karnavian, referring to the far reach of ISIS.
Indonesia's crack anti-terror unit, Detachment 88 (Densus 88), has uncovered a string of new local terror cells after Jakarta was struck by an ISIS-inspired attack in January.
Most, if not all, of these cells had received money and learnt to make bombs and mount attacks from Indonesian ISIS fighters in Syria, who send instructions home using Telegram, a smartphone messaging app, said General Tito.
But a new trend emerged earlier this month, when Densus 88 busted a group plotting to bomb the presidential palace in Jakarta.
According to Gen Tito, the suspects had not only acquired funding from ISIS fighters in Syria, but also received orders to set up smaller and harder-to- detect cells, as well as recruit Indonesian women as suicide bombers.
"Until now, security officials have focused only on prospective male attackers, and that is why Bahrun Naim's group switched to something new by using a woman as a suicide bomber," said University of Indonesia terrorism expert Ridwan Habib, referring to an Indonesian militant in the Middle East fighting alongside ISIS.
Indonesia and Malaysia have recorded their first terror attacks this year, claimed by ISIS, while Philippine President Rodrigo Duterte said the group has taken root in the country's southern island group of Mindanao.
All three countries have also experienced a surge in domestic terrorist activities in the past year.
However, it is not just the new tactics that are raising concerns, but also how ISIS has been expanding its reach in South-east Asia by appointing local proxy leaders.
Experts said the region's long history of militancy and rising number of extremist groups adopting ISIS ideology make South-east Asia attractive to the Sunni extremists.
ISIS has been priming the southern Philippines, where the Abu Sayyaf militant group operates, as its wilayah, or state.
Pirates linked to Abu Sayyaf have kidnapped dozens of Indonesian and Malaysian sailors and made millions of dollars in ransom.
Indonesian armed forces chief Gatot Nurmantyo said the recent rise in such abductions is a strong indication that ISIS is raising funds to build a base in Mindanao.
Perhaps the biggest fear for security agencies next year is the rise of a new generation of local militant leaders who have declared their allegiance to ISIS.
Indonesia has Bahrun and Bahrumsyah - the latter appointed by ISIS leader Abu Bakr al-Baghdadi to lead a battalion of foreign fighters from South-east Asia who joined the group in the Middle East.
Malaysian Muhammad Wanndy Mohamed Jedi is now the terrorist most wanted by the country's Special Branch for his hand in a grenade attack.
Malaysian police have also nabbed 115 terror suspects this year - up from just four in 2013.
The Philippines has had to contend with Isnilon Hapilon, a former Abu Sayyaf commander who was hand-picked by al-Baghdadi to be emir, or leader, of militant groups in South-east Asia loyal to ISIS.
A recent Counter Terrorist Trends and Analysis report said unlike previous South-east Asian jihadist leaders, these new militants have operated from overseas with impunity, issuing instructions and directives, transferring funds and facilitating travel for jihadists.
Indeed, Gen Tito summed it up best: "I think while ISIS exists, we should stop dreaming of an Indonesia without terrorism."
•Additional reporting by Raul Dancel in Manila and Shannon Teoh in Kuala Lumpur
This article was first published on December 21, 2016. Get a copy of The Straits Times or go to straitstimes.com for more stories.