Stalin is the model. Burma's generals are following the Soviet dictator's sadistic approach to justice: rearresting political prisoners just as their term comes to an end, introducing spurious new charges and sentencing them to a further long term in prison or a labour camp. Aung San Suu Kyi, the opposition leader who has spent 13 of the past 19 years under close house arrest, was due, under Burmese law, to be released in two weeks' time. Yesterday, however, she was taken from the house where she has been isolated for the past five years to a notoriously harsh prison, accused of breaking the terms of her house arrest and threatened with a further five years in jail. It is the despicable, cowardly act of a junta that fears the moral authority of a Nobel Peace prizewinner and is determined to break her spirit as well as her health.

The pretext is absurd. Ms Suu Kyi is accused of allowing a 53-year-old American psychology student to pay her an unauthorised visit and stay two days in her compound. John Yettaw swam across a lake to reach her, apparently unnoticed by the guards and unhindered by the security presence around Ms Suu Kyi's house. His motives remain unclear, although he made a similar attempt last year. Whatever the explanation, the generals have found in this modern Leander a pretext to keep the leader of the National League for Democracy in prison until after next year's promised multiparty elections - a clear indication that, even now, the junta is planning how to rig the vote to remain in power.

Ms Suu Kyi is a woman of great courage. Time and again she has stood up, frail and isolated, against the junta's attempts to silence, bribe or exile her. She refused the one-way ticket out of Burma to visit her British husband when he was dying of cancer in 1999. She has never compromised on the principle of a free vote, despite attempts to enlist her in a sham deal that could be presented to her supporters as a political concession. Even while held incommunicado, she has exuded the powerful moral authority that inspired many Burmese to support the doomed attempt by Buddhist monks to demand basic freedoms and human rights in 2007.

Whatever the outrage at her brutal treatment, however, the truth is that the West has little leverage. The two countries that matter most to Burma are China and India, and neither yet is ready to assume the responsibilities that must surely come with power. China sees Burma as a strategic ally, offering oil, raw materials and a deep-water port for the Chinese Navy. India also has no interest in confrontation: Burma abuts India's small, isolated and unstable states in the northeast that are plagued with rebellion and separatism. India needs stability on the borders and co-operation in halting arms smuggling.

The Obama Administration has begun a review of policy on the junta, concluding that neither engagement nor punishment has worked. That does not presage any softening: senators Obama, Biden and Clinton all voted for renewed sanctions last year after Rangoon's refusal to accept foreign help after the cyclone. But even if sanctions continue, change will probably come only if the junta sees the need for development and an end to Burma's pariah status.

Its proposed “road map to democracy” poses a dilemma to the opposition. Should it boycott the election, knowing that intimidation will deliver the vote to the generals? If it does, it loses all influence and makes it easier for timid neighbours to argue that the junta has done enough to restore democracy. If it takes part, it may win a few seats but will compromise its principles. The key remains Ms Suu Kyi. The junta is taking no risk that her voice will be heard. She will not compromise. Neither should the West.