Thai political turmoil has left the army with free rein in the south, prompting widespread human rights violations, activists say, while militants are turning to increasingly sophisticated technology to terrorise communities.
The number of deaths has dropped as the military conducts its massive campaign, but rebels have scaled up their onslaughts using car and roadside bombs, while beheadings and the mutilation of corpses continues.
"Although the number of incidents decreased in 2008, the attacks are greater in terms of destruction," said Mohammad Yub Pathan, a researcher with independent monitoring group Intellectual Deep South Watch.
"Also, the militants have acted much more systematically and with clear control and organisation."
In early November, a car bomb and a motorcycle bomb ripped through a market and a tea shop in Narathiwat province, injuring 70 people, in the biggest single assault on civilians since the rebellion began.
These are issues awaiting Thailand's fourth prime minister in the space of a year, Abhisit Vejjajiva, who vowed soon after he was elected by parliament on December 15 to ease the southern tensions.
His Democrat Party counts the south as one of its strongholds, and this will be the party's first chance in government since the rebellion broke out.
But Sunai Phasuk, Thai consultant for Human Rights Watch, said that successive governments have failed to make good on their promises to quell the southern bloodshed because their words were not followed up by action.
"One of the first issues for him is to show that there can be justice for Muslims in the south," Sunai told AFP.
The insurgency dates back to 1902, when Buddhist Thailand -- then known as Siam -- annexed the mainly Muslim and ethnic Malay far south.
Tensions bubbled under the surface, occasionally flaring up over the decades, and erupted into the current rebellion on January 4, 2004, when militants raided a southern army base, killing four soldiers.
The pace of deadly violence has picked up steadily, with 2007 seeing a record 1,015 deaths in the provinces of Narathiwat, Yala, Pattani and parts of Songkhla province, police figures show.
About 3,500 people have lost their lives during the four years of insurgency, including at least 600 people killed in 2008.
Although the rebels' aims are broadly understood to include self-rule, the conflict's murky nature is also hampering efforts to curb the violence.
"You can't identify any clear set of demands coming out of this movement," said Duncan McCargo, an academic and author of a book on southern Thailand.
"Their grievances are essentially against what they see as abuses of power by the Thai state and the historical sense that the southern border provinces are not really part of Thailand and should not be administered in the same way as the rest of Thailand."
Also frustrating efforts to subdue the rebellion are the protracted protests and political turmoil in Thailand.
"Frequent changes of government mean we don't have control over counter-insurgency and other operations in the south by an elected government," said HRW's Sunai.
"Everything in the south is in the hands of the military, who are not open to any accountability and scrutiny."
Sunai says that until authorities start prosecuting security officials accused of rights abuses including torture, killing and arbitrary arrest, the Muslim community's mistrust of the state will continue.
Amnesty International will release a report this month documenting cases of torture by security forces in the south.
But McCargo said that the southern unrest remained largely a political issue, and until serious discussions began on some elements of self-rule in the region, the bloodshed would continue.
With Abhisit heading a delicate coalition and relying on the support of the powerful army, that looks increasingly unlikely.
"Abhisit... will be very vulnerable to attack (politically) if they support any sort of government for the south or seem to be selling out in any way on the security line on the south," McCargo told AFP.