MANILA, Philippines -- The Philippines hailed the Association of Southeast Asian Nations on Wednesday, saying it allowed peace and trade to flourish in the region after the Cold War years, but leftwing groups blasted its failure to halt strongman regimes and human rights abuses.

The contrasting views reflected ASEAN's uneasy legacy as Southeast Asian countries marked on Wednesday the 10-nation bloc's 1967 founding with speeches and the launch of a commemorative regional stamp.

Activists picketed Myanmar's embassy in Manila to demand the release of pro-democracy activists, led by Nobel laureate Aung San Suu Kyi, who are detained in the military-ruled nation.

Southeast Asia "has become a showcase of how disputes can be peacefully resolved between nations," Philippine Foreign Secretary Alberto Romulo said in Manila. "Adherence to this fundamental principle has also given rise to unprecedented growth and stability in the region."

Founded during the Cold War years, ASEAN has evolved into a bloc that now includes socialist and democratic countries that are rapidly integrating their economies and collectively dealing with security concerns, he said.

Romulo cited a decade-old ASEAN treaty that forbids nuclear weapons in the region and a recent decision by its foreign ministers to create a human rights body under a proposed landmark charter as among regional efforts to foster conditions conducive to trade and development.

Leftwing groups, however, said ASEAN's founding principle of noninterference in each other's domestic affairs have fostered dictatorial regimes and allowed rights abuses to continue in the region. Abusive regimes like Myanmar have been able to somehow legitimize their image with their ASEAN membership, they said.

"If Burma can get away with murder would that make ASEAN successful?" asked leftwing Representative Loretta Ann Rosales, a member of a Southeast Asian group of parliamentarians seeking democratic reforms in Myanmar, also called Burma.

Myanmar's dismal human rights record has been the target of Western criticisms and trade sanctions. It has embarrassed more liberal ASEAN members, including the Philippines, Indonesia, Malaysia and Singapore, which have called on fellow member Myanmar to hasten progress on a promised roadmap to democracy.

Amid Western criticisms, ASEAN members have decided to engage Myanmar and not isolate it in a bid to prod it to more rapidly democratize as it struggles toward economic development.

Leftwing Representative Teodoro Casiño said ASEAN's efforts to bolster the region's economy through free-trade deals have not benefited the poor given the vast number of impoverished people in the region.

"ASEAN looks good on paper," he said. "But it has a long way to go in terms of human rights protection and fostering real democracy."

ASEAN consists of Brunei, Cambodia, Indonesia, Laos, Malaysia, the Philippines, Singapore, Thailand, and Vietnam. It accepted Myanmar as a member in 1997 despite opposition from Western governments.