In comparison, he said, Cambodia had “not recovered yet from its difficult history and the political system is too personalised around Prime Minister Hun Sen”.

Lee also dismissed Laos as an “outpost” for China, saying Vientiane reported back to Beijing on the content of all ASEAN meetings.

The ASEAN bloc was founded in 1967 as a bulwark against the expansion of communism in Southeast Asia, with Indonesia, Malaysia, the Philippines, Singapore and Thailand as members.

Vietnam joined in 1995, with Laos and Myanmar following suit in 1997. Cambodia was the last to join, in April 1999, after the July 1997 factional fighting led to a delay in its full membership.

Foreign Ministry spokesman Koy Kuong said yesterday that he did not wish to comment on the cable’s contents. “We have to read it carefully and try to understand it deeply. Right now, I do not want to make any comment,” he said.

A regional observer based in Singapore said Lee’s views on Cambodia, Laos, Vietnam and Myanmar reflected widespread fears that a “two-track” ASEAN had developed since the 1990s.

But the analyst, who did not wished to be named due to the sensitive nature of the cable’s contents, said he was surprised Lee would harp on the anticommunist origins of ASEAN, since by about 2000, the bloc was “well into the process of reinventing itself as much more than an anticommunist grouping”.

“In retrospect, there’s a real need to reassess [Lee’s] perspective,” said the observer.

US embassy spokesman Mark Wenig declined to comment in detail, except to say that Washington “fully supports Cambodia’s participation in ASEAN”. Officials at the Singaporean embassy in Phnom Penh could not be reached for comment yesterday.

Lee’s comments were made during an October 16, 2007, discussion with then-US Ambassador to Singapore Patricia L Herbold and Thomas J Christensen, then-deputy assistant secretary of state for East Asian and Pacific affairs. Lee, 87, now holds the title of “minister mentor” and remains a highly influential figure in Singaporean politics.

In other parts of the cable, Lee described Myanmar’s ruling generals as “dense” and “stupid” people who have mismanaged the country’s vast natural resources. “Lee said dealing with the regime was like ‘talking to dead people’,” the cable said.

In a separate cable released by WikiLeaks yesterday, a Chinese official cited the Cambodian peace process as an example of the benefits of increased cooperation between the US and China.

The cable was sent by the US embassy in Beijing in March 2007 and detailed talks between a top US State Department official and China’s assistant foreign minister Cui Tiankai.

The cables are just two of more than 250,000 American foreign policy documents WikiLeaks has been releasing gradually since November 28.

A total of 1,477 had been released as of yesterday evening. The WikiLeaks archive also includes 777 cables from the US embassy in Phnom Penh, none of which has been released so far.

ADDITIONAL REPORTING BY AFP