Three months have passed since the world called on Burma's dictators, Gens. Than Shwe and Maung Aye, to end their brutal crackdown on tens of thousands of peaceful monks and other demonstrators and begin a genuine dialogue with Burma's democratic and ethnic minority leaders — with the goal of a transition to democracy. The time has come for them to act.

With the strong backing of the U.N. Security Council, U.N. special adviser Ibrahim Gambari has made two trips to Burma, also called Myanmar, since the crackdown to try to facilitate a dialogue. Through him, democratic leader and Nobel Peace laureate Aung San Suu Kyi has reaffirmed her willingness to participate in a "meaningful and time-bound" dialogue to be joined by representatives of the country's ethnic minority groups.

This is a rare opportunity to help put Burma on the path to democratic civilian rule and to greater stability and prosperity. But while the regime initially made a few unremarkable gestures, such as appointing an official to interact with Aung San Suu Kyi and allowing her to meet once with a few democratic colleagues, it has since halted even this hint of progress and, in fact, has moved backward.

It has continued to arrest activists and harass Buddhist monks, recently closing a monastery that served as an AIDS hospice. Aung San Suu Kyi remains under house arrest, and the junta has refused her request to have two colleagues serve as liaisons to the government. On Dec. 3, senior regime officials delivered their harshest comments yet, rejecting any role for the opposition in drafting the constitution, blaming Aung San Suu Kyi for the lack of progress on a dialogue and describing the September demonstrations it suppressed as "trivial."

The United States does not regard such violence and the beating, detention and reported torture of peaceful protesters, including monks, as trivial. As first lady Laura Bush has said, "it seems the generals are indifferent to the Burmese people's suffering, but the rest of the world is not."

Dialogue would enable the Burmese people, through legitimate political and ethnic representatives, to discuss with the regime ways to broaden the political process — including participation in the drafting of a constitution. This way the results will have legitimacy and popular support, allowing the full array of talent available in Burmese society to tackle the country's many problems. While the regime argues that it is the only force capable of keeping the country unified and that any change outside its control risks turmoil and instability, the reality is that the regime and its policies are the greatest threat to Burma's unity, stability and prosperity.

The military rulers have brought about a steady decline in living standards and a deterioration in educational and public health systems. They have caused a continuing flow of refugees, narcotics and dangerous diseases into neighboring countries, and have so distressed and frustrated the people that they took to the streets by the thousands despite the risk of brutal suppression.

This is a horrendous track record, but Aung San Suu Kyi and other democratic leaders have nevertheless said that the Burmese military has an important role to play in a peaceful transition to democracy. With Than Shwe and Maung Aye showing no willingness to move in this direction, many in their regime should be increasingly uncomfortable with their policies and the country's direction.

The United States wants to see a strong, prosperous, stable and free Burma. We are convinced that the only way to achieve this objective is through the sort of broad national dialogue that U.N. special adviser Gambari is trying to facilitate with Security Council support. That's why it is critical that China, India, the ASEAN countries and Burma's other neighbors use any and all influence to support the U.N. effort and press the regime to initiate a dialogue. It is also why the United Nations should quicken the pace of its diplomacy.

As part of this effort, the United States will continue to target regime leaders and their cronies with sanctions. President Bush has promised that our country will continue to pressure the Burmese dictators to ensure that there is no return to business as usual. The world must not turn its back on the people of Burma and allow the regime's disregard for human dignity to continue. Together, we must apply sustained and strong pressure while making clear that a successful dialogue leading to a political transition would enable Burma to make a full return to the international system.

There are steps the junta could take immediately that would signal its seriousness — releasing Aung San Suu Kyi and others, allowing them freedom of association and ending the ongoing crackdown. Meanwhile, Ibrahim Gambari plans to return to Burma soon. It is time for the generals to tell him — and the Burmese people — that they will begin a genuine dialogue and take the steps necessary for it to succeed. The time has come to ask the senior generals: What are you waiting for?

R. Nicholas Burns is U.S. undersecretary of state for political affairs. He wrote this commentary for The Washington Post.