Burma, one of the world's most repressive military regimes,stunned the international community by abruptly freeingAung San Suu Kyi-- Nobel peace prize winner and champion of the southeast Asian country's democracy movement -- from six years of house arrest. As hundreds of supporters gathered in a light rain outside her home in Rangoon, historically laconic military leaders merely noted that her sentence had expired. "No one expected this to happen," saysTIME's Sandra Burton, in the Burmese capital. "The move indicates far greater confidence on the part of the junta that neither Suu Kyi nor the people will rush to overthrow it." That confidence may have a solid economic foundation: though some U.S. conservatives credit their threats of economic sanctions, Burton says the results more likely stem from a "constructive engagement" policy in which Japan, the Philippines and other Asian trading partnersquietly pressured the regime on human rights."The story is how one of the world's most isolated countries is bidding to join the dynamic East Asian mainstream by opening up its economy while keeping a tight grip on the political system," Burton says. The next test: whether the junta will let Suu Kyi's overwhelmingly popular National League for Democracy play a true political role. "If so, this rich but backward country could be in for a takeoff that would rival that of Vietnam." Burton says. "If not, more of the brutality and bloodshed that have held it back for four decades could be in store."