By dispatching troops into the streets and imposing a curfew, Myanmar’s cruel military junta has set the stage for a serious clash with pro-democracy activists. A firm and united international response along the lines outlined by President Bush and the European Union at the United Nations yesterday offers the best hope of encouraging peaceful change in a nation that has endured a 19-year reign of fear. The question is whether the countries with the greatest influence on Myanmar’s generals  China, Russia and India, which all sell weapons to the army, as well as the members of the Association of Southeast Asian Nations that are Myanmar’s immediate neighbors  have the good sense to condemn the repression and exert the pressures only they can wield with any hope of positive effect. It is essential that they step up to the plate, and fast, before blood is spilled.

Peaceful protests that began last month over dramatically increased fuel prices became seriously threatening to the junta when Myanmar’s highly revered Buddhist monks joined in. The growing crowds gave voice to pent-up grievances  and the junta responded in a predictable, entirely wrongheaded way. It sent troops into the streets, and Daw Aung San Suu Kyi, the iconic democracy leader and Nobel Peace Prize winner, was reported to have been moved to prison from house arrest.

The United States, which has long had sanctions on Myanmar, including an import ban, will now expand a visa ban against regime leaders and tighten financial penalties, Mr. Bush told the United Nations. Although not spelled out, the plan is believed to include going after regime bank accounts in Singapore and other Southeast Asian countries, a tactic used by Washington with some effect against North Korea. The European Union also warned the junta that it faced tougher sanctions if it used force to crush the pro-democracy movement.

These were good and necessary moves, but the greatest leverage to forestall disaster lies with China, Russia and India, who are making money off the junta and enabling it to stay in power. China, Myanmar’s chief trade partner and the host of the 2008 Olympic Games, has beefed up arms sales to Yangon, formerly Rangoon, prompting Russia and India to do likewise as a way of offsetting Beijing’s influence.