When Indonesia gained independence in 1945, there was much debate between nationalists who called for a pluralistic state and Islamists who wanted a religious state ruled by Islamic law or Sharia. The country's founders chose religious tolerance.
But the question of Islam's role in the country continues to test the limits of Indonesia's national philosophy, known as Pancasila, especially its tenet of religious tolerance.
The idea of Pancasila (derived from Sanskrit and literally meaning "five principles") was adopted on June 1, 1945 as the basic foundations of a newly independent Indonesian state. These philosophical components embodied a harmonious society based on religious tolerance, humanity, unity, democracy and social justice.
Support for Indonesia's founding philosophy remains strong in some quarters. But as the country nears its seventh decade, its roots are being tested.
More radical Islamic groups are making inroads into Indonesian society than ever before, and some have called for the adoption of Sharia by the state. While this has been rejected at the national level, Indonesia's Islamists have succeeded in imposing Sharia in some districts and municipalities at the local level.
Ulil Abshar Abdalla, a Muslim scholar and co-founder of the Liberal Islam Network and Freedom Institute, says Islamists have found room to manoeuvre due to "an ideological void" left by the end of the New Order regime set up by former military ruler General Suharto.
In a speech last month, President Susilo Bambang Yudhoyono recognised a need to revitalise state ideology to counter radicals who insist on making the Muslim-majority archipelago a religious state - which has dangerous connotations for a nation that has championed a policy of tolerance.
Indonesia's approach to governing could be seen as a model for other Muslim-majority nations, especially during this season of profound change in the Arab world. In Egypt, for instance, the Islamist Muslim Brotherhood is making a comeback. (While some Brotherhood members have called for a more radical application of Sharia law, many have moderated their positions).
Indonesia is pushing in the opposite direction.
"Indonesia is not in the position to lecture, to tell Egypt, for example, to imitate or to follow our path," President Yudhoyono said during a recent interview with a group of journalists from the United States. "But Indonesia can share our experiences, our successes, and our failures in conducting reforms."
Pancasila is a critical piece of Indonesia's success, he says.
Indonesia's cabinet secretary Dipo Alam agrees. He says the five principles are the only "solution" to maintaining peace and harmony in a multi-religious archipelago of more than 17,000 islands, with over 300 ethnic groups speaking 250 languages.
Nonetheless, force-feeding tolerance has not always won high praise.
Pancasila gained much notoriety during the Suharto years when he used it as a political tool to suppress political dissent. Even today, for disaffected groups, especially in the restive regions of Aceh and Papua, Pancasila's promise of humanity, social justice and democracy is far from reality.
Widya Fitri, a student of international affairs at the University of Indonesia in Jakarta, says marginalised sections of society do not hold Pancasila in high regard. But, she adds, the concept is important to "avoid the worst possibility in the future" - the country's break-up.
So far social justice, one of the five tenets of Pancasila, rings hollow for the 13 per cent of the country's population - over 32 million people - who still live below the poverty line. Aware of this, Indonesia's House of Representatives recently proposed that schools should have lessons in the founding philosophy.
It has not been an easy sell. Yohanes Sulaiman, a lecturer at the Indonesian National Defence University, argues this would not do much to help the ideology regain its prominence in the mind of Indonesians. Instead, the president should "encourage honest discussions on Pancasila", he writes, "not just simply imposing rigid doctrinaire interpretations".
Ultimately, Indonesians must come to Pancasila on their own, convinced of its benefits as an essential bond for a diverse, potentially fractious nation. There have been efforts to make Pancasila more hip and accessible through popular songs and with T-shirts adorned with the term. Saykoji, a popular artist, raps about the importance of Pancasila to preserving the country's unity and diversity.
Muhammad Fadel, a third year student of economic and financial management at University of Indonesia, says these nationalistic songs resurface during soccer tournaments with other Southeast nations and during Asean games. When it comes to a symbol of Indonesian unity, the national emblem, Garuda (a mythical bird) with the five principles of Pancasila emblazoning a shield on Garuda's chest, remains the nation's favourite.
Pancasila is and will remain uniquely Indonesian; it cannot be replicated in other Muslim nations yearning for a more inclusive approach to religion and tolerance. But perhaps it can serve as a blueprint.
Jayshree Bajoria is a senior staff writer on Asia for CFR.org, the website of the Council on Foreign Relations. She travelled to Indonesia on a Gatekeeper Editors' trip organised by the International Reporting Project (IRP) in Washington, DC.