NEW YORK — “The most important contest in the world right now is between the ISIS model and the Tunisian model,” said Rachid Ghannouchi, who was visiting New York this week. “It’s not between Islam and the West. It’s between ISIS and us.” Ghannouchi is the intellectual leader of Ennahda, Tunisia’s Islamist party that, despite winning the country’s first free elections, compromised with its political foes, relinquished power, and helped make Tunisia the Arab Spring’s only success. He explained why his small country’s story is crucial to the struggle against militant Islam across the world.

“The only way to truly defeat ISIS is to offer a better product to the millions of young Muslims in the world. We do: Muslim Democracy,” he said. “Young people don’t like ISIS — see how many millions flee from it — but they won’t accept life under tyrants either.” He elaborated that the “better product” needed to be a political system that was genuinely democratic and respected human rights but also allowed Islam and its values some space within the political system. “We are building the alternative model in Tunisia,” he told me proudly.

Ghannouchi said that, in his view, the thousands of young men traveling to join the Islamic State were similar to discontented firebrands who became Marxist guerrillas in the 1950s and 1960s. “Some people search for an ideology of violent protest against the established order. That’s not strange,” he said. “It has taken a religious garb today.”

“How did we get these Islamic terrorists?” he asked. “Throughout the Middle East, for decades, dictators suppressed Islam. In Tunisia, any kind of Islamic education was forbidden. It was forbidden for women to wear the veil. People were persecuted if they demonstrated any interest in Islam. It is these policies that produced a reaction, the generation of Islamic terrorists that we are living with now.”

Tunisia’s success story is not quite the fairy-tale version that is sometimes recounted. The Islamists pushed for greater influence of Islamic law, they were reluctant to compromise and left power only because they thought the country would explode if they didn’t. Key elements of the old guard have returned in force and the place remains fragile, with the economy under severe pressure.

But most transitions to democracy are marked by bitter struggles. Democracy did not come amicably to South Korea, Taiwan or Chile. The dictators resisted fiercely. There were riots, mass arrests and street violence. It is only in retrospect that one can look back and speak calmly of peaceful democratic transitions.

Tunisia has some distinct advantages that have helped it along. In a conversation with the country’s head of government, Habib Essid, a technocrat, I asked him to explain the country’s success. First, he pointed out that Tunisia has existed as a political entity for 3,000 years (from the times of ancient Carthage). Second, he noted that Tunisia is almost entirely Sunni, so it does not have the sectarian and tribal differences that create fissures in other lands like Iraq, Syria and Libya, which have been modern nation-states for less than 100 years.

Third, he explained that under its first post-independence leader, Habib Bourguiba, Tunisia built strong political and administrative institutions. Ghannouchi highlighted another key advantage: Bourguiba ensured that the military was restricted and nonpolitical. Referring to the Egyptian military’s return to power and its dismissal of democracy, he said, “In Egypt, the army has a country. In Tunisia, the country has an army.”

In addition to all these structural and historical advantages, Tunisia has benefited from wise political leadership. Ghannouchi explains why his party compromised. “The old guard might have lost the election but it was still very powerful. It was the elite of the country. So we had to make deals with them.” You cannot go for total victory, he said; the goal has to be consensus. “In a stable democracy, if you win the election, perhaps you can do everything your way. But in a young democracy, we need consensus and compromise.”

“We lost power,” Ghannouchi said, “but we won Tunisia.”

Ghannouchi remains optimistic about the Arab Spring. “People will not go back to the old ways of tyranny. Like the French Revolution, the Arab Spring has produced turmoil and violence and reaction — but eventually it will transform all these dictatorships and monarchies in the Muslim world.”

Fareed Zakaria is a syndicated columnist. His email address is: comments@fareedzakaria.com.