Lee Kuan Yew’s Singapore had only two years earlier separated from Malaysia. The “Domino Theory” had us believe that Mao-inspired revolution was set to topple regimes across South East Asia.

At this exact moment, foreign ministers from Asean’s five “founding fathers” – Indonesia, the Philippines, Malaysia, Thailand and Singapore – gathered in the Foreign Ministry in Bangkok to forge an agreement that in the following decades transformed the region from a battlefield to a marketplace. One of the leading South East Asia scholars of the period noted a couple of weeks ago with no hint of jest: “Given the turmoil at the time, those founders deserved the Nobel Peace Prize.”

Look back into the text of the Bangkok Declaration that forged Asean, and it is hard to disagree: “The collective will of the nations of South East Asia is to bind ourselves together in friendship and cooperation, and, through joint efforts and sacrifices, secure for their peoples and for posterity the blessings of peace, freedom and prosperity.”

Malaysia’s Tun Abdul Razak captured the mood: “We share a deep awareness that we cannot survive for long as independent but isolated peoples unless we think and act together.”

Indonesia’s Adam Malik said that his country’s vision – as by far the biggest, but one of the poorest nations in South East Asia – was for “a region which can stand on its own two feet, strong enough to defend itself against any negative influence from outside the region.”

The common immediate fear galvanising them to create Asean was from a dangerously unpredictable communist China that was malevolently fanning the flames of communist radicalism in every country in the region, but painful shared memories of colonial rule provided a quiet subtext.

It is often fashionable today to be dismissive of Asean’s achievements over the following 50 years, particularly among those who believed South East Asia’s leaders had set themselves on a course similar to that of Europe’s leaders in the European Union.

But once you push this canard to one side (no Asean member ever had any interest in giving away its sovereign powers) and remember the chaotic origins from which it was conceived, and the remarkable diversity of the region, the achievements are nothing short of awesome.

Indonesia’s economy has grown more than 150-fold since 1967, Thailand and Malaysia 70- to 90-fold, and even the laggard among them, the Philippines, growing 40-fold.

In 1967, Europe’s economy was 28 times larger than that of the Asean founders. Today, with both Asean and the EU expanding significantly, Europe is just six times bigger. The US was originally 36 times larger, but today is just seven times larger.

For Indonesia and Singapore, per capita gross domestic product (GDP) has soared 70-fold, and both Thailand and Malaysia have seen a jump of 35 times, and 28 times respectively. The Philippines, which started out as the largest of the five founding economies, has been the disappointing laggard, but even here GDP per capita has jumped 15-fold.

Perhaps most significant of all, in spite of South East Asia being one of the most diverse cultural and political regions in the world, is the single triumph that it has endured. No dominos have fallen. Some argue that Asean should be seen as the world’s second most significant institution in the world after the EU. Whether you buy that logic, what is nevertheless indisputable is that the 10 member economies together amount today to the world’s seventh-biggest economy.

The Asean Economic Community may be a patchy work in progress, but it has worked well to build on the founding fathers’ vision of a region that can stand on its own two feet, that can think and act together. Cooperation across the region is underpinned by more than 1,000 Asean meetings every year – which could be expanded to 1,400 or so if Apec meetings are included (seven of the Asean member states are in Apec, the Asia-Pacific Economic Forum).

It can fairly be argued that Asean’s journey would have been very different if Deng Xiaoping had not come to power in 1978, profoundly shifting the nature of China’s relationship with the outside world. In 1967, China’s main export was communism. Today it is Chinese tourists. Today, China and the Asean economies are tied tightly together along thousands of global manufacturing supply chains, and by ambitious Chinese initiatives like the Belt & Road Initiative, and the Asian Infrastructure Investment Bank. They have forged a Free Trade Agreement.

But just as the challenge of managing relations with China was a key catalyst for Asean’s founding fathers, so the same challenge quietly (and sometimes not so quietly) shapes the priorities of Asean’s leaders today.

An increasingly muscular China that is busily building blue water naval capability is a massive concern to Asean members, in particular focused on potential conflict in the South China Sea.

Perhaps the single strongest message to China from Asean leaders must be that as Beijing leaders scour the security horizon across its northern, western, southern and south eastern borders, Asean provides the model peaceful border, and provides the potential for wider regional harmony. With so many of China’s other borders looking far less friendly, there must surely be merit in calming the South China Sea’s troubled waters.

So Asean’s 50th anniversary is a landmark worthy of serious celebration. For Hong Kong, which has long neglected the South East Asian economies because of its perfectly understandable obsession with developments to our north, there will hopefully be a second serious reason for celebration later this year: completion of Hong Kong’s long-overdue Asean free trade agreement.

We have down-played an economic region of more than 600 million people for far too long. Perhaps on its 50th anniversary, we can make amends.

David Dodwell researches and writes about global, regional and Hong Kong challenges from a Hong Kong point of view.