"Let us fix Mindanao", beseeched Philippines President Rodrigo Duterte in the final leg of his presidential campaign in front of thousands of enthusiastic supporters. "I am pleading with you, let us fix this. We belong to one nation."

As the first successful presidential candidate from Mindanao, Duterte has never failed to remind the Catholic-majority electorate about the moral and political obligation to "correct the historical injustice committed against the Moro people".

Time and again, Duterte has emphasised his own Muslim heritage, through his maternal ancestors, presenting himself as the president for all Filipinos, including the Moro minority.

In one of his particularly emotional presidential campaign speeches, Duterte promised, "If I become president, if Allah [God] gives his blessing, before I die since I am old, I will leave to you all a Mindanao that is governed in peace."

Duterte's presidency meant a historic opportunity to rally a diverse and divided nation under the same flag. Eight months into office, however, Duterte is confronting the prospect of full-blown terrorism in Mindanao, as affiliates of the so-called Islamic State of Iraq and the Levant (ISIL, also known as ISIS) expand their area of operations with renewed vigour, beheading one hostage after the other.

Reign of terror

The ongoing conflict in Mindanao is the latest iteration of a centuries-old struggle for domination of the Muslim-majority regions of the Philippines. At its very heart, it is about a struggle for autonomy and self-determination.

The Filipino Muslim (Moro) minority, which reigned supreme during the Medieval and Renaissance periods, has had to contend with the triple challenges of the Spanish inquisition, American colonisation, and coercive assimilation under "imperial Manila" in modern times.

Devastated by civil strife, terrorism, and all-out armed conflict, Mindanao suffers from one of the highest rates of poverty, illiteracy and unemployment anywhere in the world (PDF).

It has among the lowest Human Development Index indicators, giving birth to an ecosystem of rage and despair, which has been exploited by extremist groups, who thrive on hatred and violence.

While major Moro rebel groups - namely the Moro National Liberation Front (MNLF) and the Moro Islamic Liberation Front (MILF) - have engaged in peace negotiations with the Philippine government, their breakaway factions have morphed into formidable and violent groups such as Abu Sayyaf and Bangsamoro Islamic Freedom Fighters.

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Initially, a combination of robust Philippine-America counterterror cooperation and determined peaceful negotiations drove these groups into the underground. In the past three years, however, after pledging their allegiance to the ISIL, which formally recognised their Bay'ah, the extremist groups stepped up their kidnap, ransom and piracy operations with frightening efficacy, with the ultimate goal of establishing a "Wilayat" in Southeast Asia.

After a spate of sea kidnappings, targeting international vessels roaming the Philippines' porous maritime border with Indonesia and Malaysia, the three neighbouring countries were forced to consider joint patrol operations.

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"The continued kidnapping and piracy there is a major concern. It is so frustrating how they continue to elude us with impunity," Philippine Secretary of Defence Delfino Lorenzana told the Financial Times.

The situation has become so dire that Duterte was prompted to give green light to Indonesia to chase the terror groups all the way into Philippine waters and "go ahead and blast them off" if necessary.

Second Somalia

More recently, Duterte went so far as threatening to declare martial law in Mindanao to stamp out terrorism and called upon China and other naval powers to conduct sea patrols in the area.

Some experts are beginning to compare the situation to Somali piracy in the Gulf of Aden, which has similarly, though on a larger scale, threatened international maritime trade.

As the chairman of the Association of Southeast Asia Nations, Duterte, is expected to place the fight against terrorism at the centre of the regional agenda. The whole Asia Pacific region is deeply worried about ISIL's inroads into Southeast Asia and the corollary prospects of a "distant caliphate" in East Asia.

To defeat extremism, Duterte will have to put the full force of his office and the sheer gravity of his charisma behind the largely frozen peace negotiations with Islamist rebel groups.

The ASEAN is scrambling to come up with multilateral mechanisms, which will facilitate expanded intelligence-sharing, tactical cooperation and joint patrols among affected nations.

The current trepidations stand in stark contrast to the overflowing optimism during Duterte's earlier months in office.

Back then, some even suggested the possibility, though half-jokingly, that the controversial and tough-talking Filipino leader could bag the Nobel Peace Prize if he managed to achieve the elusive peace that repeatedly slipped through the grip of even his most capable and genuine predecessors.

'The ultimate saviour'

Practically all major rebel groups looked up to him as the ultimate saviour, a man who could unlock the mystery of peace.

Blessed with unprecedented political capital, a longtime friend of rebel leaders such as Nur Misuari (founder of the modern Moro nationalist movement), a person with Muslim heritage and the venerable son of Mindanao, Duterte was in a uniquely auspicious position to end the decades-long conflict in his home island.

Yet, so far the Filipino leader has expended much of his political capital on a controversial war on drugs, which has invited heavy criticism from across the world, and seemingly fruitless peace negotiations with communist rebels, which are preparing for a new round of all-out war.

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To defeat extremism, Duterte will have to put the full force of his office and the sheer gravity of his charisma behind the largely frozen peace negotiations with rebel groups.

This is the Filipino president's best shot at mitigating the ecosystem of terror and fulfil his campaign promise of lasting peace on his home island of Mindanao. Duterte may after all still be the Philippines' last hope for unifying a broke nation.

Richard Javad Heydarian is a specialist in Asian geopolitical/economic affairs and author of Asia's New Battlefield: The USA, China, and the Struggle for the Western Pacific.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.