Three years into his presidency, Rodrigo Duterte signed the Bangsamoro Organic Law, previously known as the Bangsamoro Basic Law (BBL).

It marked a historic step towards the creation of a Muslim-majority sub-state entity within the Catholic-majority Philippines. It also represented, to this date, Duterte’s biggest legislative achievement.

The path ahead, however, remains bumpy and uncertain. Residents of Muslim-populated regions in Mindanao are yet to approve the creation of a Bangsamoro (nation of Moros) in a plebiscite later this year.

Lurking over the horizon are the dark clouds of tribal-ethnic divisions, poor basic infrastructure, and an overall climate of insecurity. Yet, to many people and experts, this is the Philippines’ best chance at staunching the wounds of a religious divide, which has haunted the fertile and beautiful island of Mindanao for centuries.

A personal legacy

As the first Filipino president hailing from Mindanao, Duterte has fulfilled his earlier promise to nudge the troubled southern island towards peace and prosperity.

Ahead of his election as the Philippines’ most powerful man, Duterte billed himself as a unifying force, the first president of the Moro people, and an unremitting advocate for Mindanao’s interests.

Against this unique backdrop, Duterte has pushed for greater autonomy and respect for the Muslim minority in the Philippines, who are among his most loyal constituents.

The final approval of the controversial Bangsamoro law served as a testament to the political will and enduring popularity of the Filipino president.

For years, the proposed creation of a Bangsamoro faced stiff opposition among the political establishment as well as the wider public, especially after the Mamasapano massacre in 2015, when rebel groups killed dozens of Filipino Special Forces during a botched counter-terror operation.

Throughout much of his two years in office, Duterte himself shunned the BBL issue, partly concerned about lack of political support. Back in May, however, he finally certified the proposed law as an urgent bill, mobilising his allies in both houses of the Congress to approve it.

In his third State of the Nation Address (SONA), Duterte placed the Bangsamoro issue front and centre. He underscored his “solemn commitment” to ensure his administration “will never deny our Muslim brothers and sisters the basic legal tools to chart their own destiny within the Constitutional framework of our country”.

Describing Mindanao as a land of promise approaching a “crossroads of history”, Duterte implored his countrymen for “loads of understanding and patience to endure and overcome the birth pangs or pains of the new beginning”.

There was a sense of urgency. He signed the Bangsamoro law less than a year after militants affiliated with the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group laid a months-long and destructive siege on the Muslim-majority city of Marawi.

Through granting greater political autonomy, Duterte hopes, the government will address the roots of extremism and terror that have hounded his country. He argued that the Filipino people “owe it to our fallen soldiers and police officers” during the liberation of Marawi to “put an end to the bloodshed and seek the path of true peace” for generations to come.

The tough road ahead

The new law provides for the demobilisation of tens of thousands of Moro rebels, as both sides hope to end a war economy that has ravaged Mindanao. Under a 75-25 wealth-sharing arrangement between the national government and the proposed Bangsamoro entity, only a quarter of locally-generated taxes will be remitted back to the national government.

The Bangsamoro will also be guaranteed an annual block grant of up to a five percent share of the entire national revenue, amounting to just over $1bn (P59 billion) annually. The region will also have its own unique domestic legislation, likely a parliament, and a plethora of distinct administrative systems, including the creation of Islamic law courts.

After a decades-long liberation struggle, led initially by the Tausug-dominated Moro National Liberation Front (MNLF) and later the Maguindanao-dominated Moro Islamic Liberation Front (MILF), the Moros are now the closest they’ve been to achieving their long-sought autonomy, though still within the framework of the Philippine constitution.

Yet, the proposed Bangsamoro, a product of a 2014 peace agreement between the Philippine government and the MILF, has been met with reticence if not derision by some leaders of the MNLF, who may fear a loss of power and prestige to their rivals under the new regime.

After all, the Bangsamoro will replace the MNLF-led Autonomous Region of Muslim Mindanao (ARMM), a largely failed earlier experiment at granting autonomy to relatively few Muslim-majority regions.

Duterte has promised to personally mediate among competing ethnic-tribal groups to unify the Moros under the new political entity. The other challenge is the willingness of more prosperous and diverse provinces, especially in Cotabato but also in Lanao del Norte and elsewhere, to join the MILF-dominated Bangsamoro.

After all, some Moro warlords and political dynasties may prefer to duke it out under the established rule of distant “Imperial Manila” rather than a more uncertain one under proximate rivals in Mindanao.

Surveys also show that the broader Filipino public is largely “neutral“ with almost equal numbers of people expressing support and opposition to the creation of a larger Muslim-majority political entity. Many Mindanao residents are either sceptical or perplexed about its implications.

There is even a chance that some critics will question its constitutionality at the Supreme Court on the grounds that this will undermine the country’s internal coherence and territorial integrity.

Above all, however, the biggest challenge is for the MILF and other regional leaders to transition from weary rebels into a competent and progressive ruling class capable of addressing the most fundamental needs of the Moro peoples.

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