The Burmese government has released a significant number of political prisoners in the latest sign that reformers have seized the initiative. On Wednesday, between 100 and 300 political prisoners were set free as part of an amnesty covering as many as 6,000 inmates. Among them were prominent opposition leaders such as Zarganar, a comedian and commentator jailed in 2008 for criticising the then junta’s disastrous response to Cyclone Nargis.Hundreds of political prisoners remain in jail. Yet the mass release was not the only sign of change in Burma, renamed Myanmar by the generals who shot their way to power in 1962. Events have moved quickly since an election last November, denounced by many as a stage-managed transfer of power from the military to a phoney civilian administration.

Change has come thick and fast. Aung San Suu Kyi, the totemic opposition leader, was released in November. Thein Sein, the new president, has initiated debate in parliament, some sessions of which have been televised. Censorship has been relaxed. Ms Suu Kyi has met government leaders. A controversial $3.6bn dam, backed by China, has been suspended in a rare snub to Beijing and concession to public opinion.

The question now is how the west should react. The answer is cautiously, but positively. Long-time advocates of democracy are rightly wary. They have seen apparent thaws before. Zarganar himself said: “I still don’t really believe that Burma is on the right track. I’m saying that based on my experience.”

Nonetheless, the west should not simply stand idly by. Reformers in Burma seem to have the upper hand. They should be encouraged. A start could be made by expanding the list of officials allowed to travel. Some of those apparently behind reform are still on the banned list. Engagement can do little harm. If change continues, particularly if it is embedded in law, the west should consider slowly watering down sanctions.

Clearly, there are dangers. The west could be taken for a ride. But doing nothing would be riskier still. If the reformers are not rewarded with concessions, they may find themselves isolated and vulnerable to a hardline counter-offensive. On balance, it looks like Burma’s government is moving in the right direction. That would make this the best opportunity for positive change in decades. The west should help push that process along. Simply standing on the sidelines of history is not an option.