The launch this week of the biggest Indonesian military operation since the 1975 invasion of East Timor suggests an impending bloodbath in the contested northern province of Aceh.

That the huge military assault on Aceh's pro-independence guerilla forces (GAM) went ahead at all represents a stunning failure for the political process. In ordering her forces to "crush" GAM, President Megawati Soekarnoputri has reached for the same brutal, but ultimately counter-productive, template of the authoritarian regime of the former president Soeharto.

Despite the democratic credentials of Mrs Megawati's government and an earlier official apology to the Acehnese people for human rights abuses committed under Soeharto, there is evidence that civilians will be no better protected in the new offensive. Civilians made up most of the 10,000 people killed in Aceh in nearly three decades of fighting.

Both sides are at fault for the breakdown of December's fragile ceasefire and the 11th-hour peace talks in Tokyo at the weekend. GAM's 3000 to 5000 guerilla fighters have shown virtually no willingness to compromise and have committed their share of violent abuses against soldiers and civilians.

But the nature of the independence struggle means the ball has always been in the government's court. Aceh's history as a fiercely independent Muslim sultanate until its incorporation into the Republic of Indonesia in 1949 – and its bitter experiences since of human rights abuses and the diversion of considerable revenue from natural gas and timber to Jakarta's coffers – always meant peace would only ever come at a price.

Unrealistically, GAM set this price as independence. Jakarta is determined, at virtually any cost, to prevent a repeat of East Timor's humiliating breakaway. And despite international concern at human rights abuses in Aceh, there is little external support for an independent state on Sumatra's northern tip.

However, Jakarta's "special autonomy" package of 2001 has proved little more than an empty phrase. There was never any real prospect for peace without genuine political representation for the Acehnese, the return of gas and timber earnings and an end to the perpetual state of fear created by long-term militarisation.

A slim hope lies in the ongoing diplomatic efforts of the United States, Japan and the European Union, which had pushed for the last-minute Tokyo talks. Despite the resort to overwhelming force there can be no decisive military solution in Aceh, only another bloody military failure.