An American freelance journalist who spent weeks with Acehnese rebels went on trial yesterday for violating Indonesian visa restrictions, charges which carry a maximum penalty of five years in jail. The start of William Nessen's trial in Banda Aceh coincided with a warning from an international think-tank that the military's massive crackdown in Aceh had failed to capture any senior insurgent commanders and was increasing popular support for the rebels. Defence lawyer Amir Syamsuddin said Nessen faced allegations that he misused his journalist visa because he wrote for more than one newspaper, that he failed to obtain a press card and that he failed to obtain permission to visit Aceh once it was placed under martial law. 'The defendant misused his Indonesian visa,' prosecutor Efdal Effendi said. Nessen, 46, who wrote for the San Francisco Chronicle and The Sydney Morning Herald, surrendered to the military and was arrested last month after the rebels he was travelling with came under attack. The case against Nessen, who is being held in custody, was adjourned to next Wednesday. Nessen's trial comes as the military implements tough new laws on the press, making it almost impossible for foreign reporters or foreign aid workers to visit the province, while local reporters have been barred from interviewing rebels. Diplomats say the military is trying to close the province off from outsiders as it did in East Timor in 1999, thus limiting reports of military abuses against civilians. But a report released by an international think-tank yesterday warned that the military's operation - aimed at wiping out rebels and undermining support for them among Acehnese civilians - is failing. 'Virtually everything it [the government] is doing now ... are tactics used before, to disastrous effect. They do not help end separatism: they generate more support for it,' says the report by the Brussels-based International Crisis Group (ICG), which investigates world trouble spots. Such tactics include the forced relocation of thousands of villagers from rebel-occupied areas into refugee camps and arresting anyone suspected of sympathising with the rebels. Nor has the military been able to wipe out the guerilla movement, says the ICG, noting that no prominent rebel leaders have been captured.