The indiscriminate, awesome power of the Indian Ocean tsunami did not just annihilate communities, it fundamentally altered the destinies of two bloody, decades-long conflicts.

In Aceh, the Indonesian province worst affected by the devastating waves, the apocalyptic aftermath has become a catalyst for peace between the Government and separatists.

It seems both parties innately understood that the fighting had to stop if this land was to get the aid required for the huge rebuilding task.

Jakarta started the final phase of a troop reduction in Aceh today, a key step in a peace agreement with separatist rebels that was propelled forward by the disaster last year.

Yet, in Sri Lanka, the sweeping rapids of a year ago appeared to have reopened festering wounds were tentatively bound up by a fragile ceasefire.

The Liberation Tigers of Tamil Eelam (LTTE), or Tamil Tigers, who effectively control Sri Lanka in the north as well as eastern parts, are angry because they have not received aid from a Government that fears the separatists will use the money to buy weapons.

Now informed observers feel that both parties are on a collision course for another civil war.

So, in the post-tsunami landscape, these two lands appear to be heading in different directions, partially because of the same, seismic event.

Some 3,800 Indonesian soldiers carrying automatic rifles and heavy bags boarded five navy ships and a Hercules air carrier today in the port town of Lhokseumawe, just days after Free Aceh Movement (GAM) rebels handed over their weapons and disbanded their military wing.

Hundreds of people also attended a ceremony marking the completion of disarmament and decommissioning, the most delicate phase of a peace deal signed in August to end the bitter conflict that killed nearly 15,000 people.

Nick Meo, who is reporting from Aceh for The Times, said: "The tsunami played a big part in this. It speeded things up."

He added: "Both sides understood that to rebuild Aceh, they had to stop fighting. There was a lot of international pressure on both sides to do a peace deal. Donors did not want to put money into a war zone."

President Susilo Bambang Yudhoyono of Indonesia summed up the general feeling about the peace deal and its relationship to the disaster this week: "Here in Aceh, we already have an example of how a new hope for peace can emerge out of the ruin of destruction."

Prospects for the region seem positive, even though a previous ceasefire ended in bloodshed after it fell apart. Meo said: "There was bitterness and distrust among both sides but that has changed now. There is real trust between the two sides now.

"Aceh is rich in gas and oil. Part of the peace process saw Jakarta agree that Aceh could keep the lion share of its natural resources."

Yet in Sri Lanka the violence is likely to be prolonged for some time. Only today the Sri Lankan army and navy recovered four anti-personnel mines set to explode near passing military convoys.

Attacks blamed on the Tamil Tigers have left 45 government soldiers dead this month in an escalation of violence that threatens a 2002 Norwegian-brokered ceasefire.

On Christmas Day masked gunmen shot dead a Tamil politician as he attended a midnight Mass with his wife and family at his side. Both sides blamed each other for the killing.

Hagrup Haukland, the chief of a group of truce monitors drawn from five Nordic countries, said in a statement: "In not so many words, if this trend of violence is allowed to continue, war may not be far away."

Dan McDougall, reporting from Sri Lanka for The Times, said that this latest phase of deteriorating relations can be traced back to how aid was distributed following the tsunami.

He said: "In Sri Lanka, the aid was kept in Colombo and withheld from the Tamil Tigers. There is an ongoing Supreme Court process in Colombo as to whether the Tamil Tigers will actually get any money.

"They [Tamil Tigers] should have been given the aid to administer because they administrate those areas [in the north and parts of the east].

"As far as the Government is concerned, they still believe the Tamil Tigers will spend the aid money weapons."

He also agreed with earlier assessments that war was likely, explaining that the separatists are angry because they claim to have received nothing of the billions given in aid to the Sri Lankan Government.

McDougall said: "There is no sanitation or food or clean water coming (in the north). The south is a very different situation. There is a great divide and the two sides are on a collision course, they both want war."

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