Irwandi Yusuf was in jail for treason when the tsunami crashed into Aceh, sweeping away everything in its path - hundreds of thousands of people, houses, cars and the walls of his cell. He scrambled to the roof and watched as hundreds of other inmates disappeared in the torrent of water.

The tsunami that took more than 131,000 lives in Aceh sprang him from prison, and in a twist of fate helped usher peace into an Indonesian province that has known war for 130 years.

The 45-year-old former fighter and intelligence agent fled to the Indonesian capital, Jakarta, then Malaysia and finally Finland where he joined exiled leaders of the Free Aceh Movement, or GAM, in negotiating an end to the fighting.

Many obstacles lie ahead but, five weeks after the signing of the Helsinki accord most people agree peace prospects have never been better.

Thousands of Indonesian troops in camouflage battle gear have left in warships - the first of 30,000 soldiers and police slated to pull out by year's end. Young rebels in blue jeans and dark sunglasses have handed in about a quarter of the 840 weapons that GAM declared as its arsenal to fight government troops.

"The tsunami changed our minds," said Yusuf, noting that tens of thousands of his fighters lost relatives in the December 26 disaster that struck 11 Indian Ocean countries.

"With so many people suffering, we want to focus now on how to rebuild."

The province on the northernmost tip of Sumatra Island is not the only place where the killer waves appeared became a catalyst for peace.

In Sri Lanka, too, foes reached across ethnic divides to help shelter and feed survivors. But today things are bloodier than ever, in part because of disputes over tsunami aid but also because the secretive Tamil Tiger rebel movement has too much to lose.

Aceh's latest fighting broke out in 1976 when rebels picked up arms to carve out an independent homeland in the oil- and gas-rich province. Nearly 15,000 people have died, many of them civilians caught up in army sweeps of remote villages.

A lot can still go wrong. Three earlier accords collapsed and some rebels are still afraid to leave their jungle bases. But others have slowly started climbing down from the mountains to visit family and friends in Banda Aceh, the provincial capital, and other areas previously off-limits to them. Some have recently ridden motorcycles along coastal roads to see the devastation for the first time.

Hundreds of thousands of Acehnese remain homeless, many in tents on trash-strewn lots that were once thriving middle-class neighborhoods.

But life is springing back: young men play soccer on a field that was littered with hundreds of bloated bodies for days after the tsunami. Lovers walk hand-in-hand along the beach, and thousands turned out recently for a pop concert.

"To have peace after a disaster like the tsunami is really heaven after hell," said Suadi Sulaiman, 27. He was strolling through rice paddies and alleyways in the village of Simbe where, until a few months ago, he was fighting or fleeing soldiers - once with a bullet in his side.

Conditions for peace were improving even before the tsunami.

The rebels were reeling from a 2003 military offensive that followed the collapse of the previous accord.

Thousands had been killed, leaving them with only 3,000 fighters pushed deeper and deeper into the jungle, the Brussels-based International Crisis Group said in a report.

Many were young, uneducated and lacked their predecessors' ideological zeal.

"We just like fighting," said Fachruvrazi, 24, who took up arms in the rebel stronghold of Pidie when he was 19. "We told our parents, `if you don't let us go to battle, we won't eat our rice."'

Weapons were so scarce that fighters had to share their guns.

In contrast, Sri Lanka's Tamil Tigers are well armed and organized. After nearly two decades of fighting that has claimed 65,000 lives, they control large swathes of rural Sri Lanka, complete with their own border guards and tax collectors.

At the same time, Sri Lanka's government has been riven by inter- party disputes and opposition to the peace process.

Those divisions were reflected in the Tigers' demand for a say in distributing the billions of dollars in aid that poured in after the tsunami killed more than 30,000 Sri Lankans. When President Chandrika Kumaratunga finally agreed, some coalition supporters abandoned her.

By contrast, the peace process in Aceh had the full support of the government of newly elected President Susilo Bambang Yudhoyono, who had promised to end festering insurgencies in Aceh and Papua provinces.

Vice President Jusuf Kalla was in secret talks with GAM even before the tsunami.

Things kicked into high gear after the December 26 devastation. As foreign aid workers poured into the province that was closed off to them during the previous two years of martial law, international pressure on Jakarta to halt the violence increased, with billions of dollars in foreign aid at stake.

The rebels said they didn't want to add to people's suffering "and we realized too that rehabilitation and reconstruction in Aceh would be impossible if there was no peace," said Kalla.

So when they met in Helsinki, both sides made big concessions. The rebels gave up their long-held demand for independence and the government agreed to give Aceh limited self-government and control over 70 percent of the revenue from its mineral wealth.

The rebels won amnesty and more than 1,400 prisoners were freed.

Are the rebels really committed to peace or this is just a tactical pause? "It's too early to know," said Ken Conboy, a private security consultant in Jakarta.

He said neither the Indonesian army nor the rebels were hard hit militarily by the tsunami: The rebels operated well away from the shoreline and the government could easily absorb the deaths of several hundred troops.

But tens of thousands of rebel family members killed in the waves had some effect on morale.

Samsul Fuadi lost his mother, father and 18-year-old sister, and still the war went on.

His final battle came two weeks after the tsunami, and made him think. Reflecting on the toll in that fight, he noted that of the seven dead, six were civilians - tsunami-stricken innocents caught in the crossfire.

"Scavengers, sifting through the tsunami's rubble," he called them. ASSOCIATED PRESS