In less than two months, Asean leaders will gather in Manila for the 49th summit and the region has set itself a test to pass before they arrive. Secretary-General Kao Kim Hourn said in May that he expected the ratification process for the Asean Framework Agreement on Petroleum Security, or Apsa, to be completed before the summit.

The agreement gained urgency in Cebu last May, when Southeast Asian leaders confronted an uncomfortable reality: the region's prosperity rests partly on systems it does not control.

Philippine Foreign Secretary Theresa Lazaro warned that Asean imports roughly two-thirds of its crude oil and remains vulnerable to external disruption. Leaders urged faster progress on Apsa and discussed regional fuel reserves. Prime Minister Anwar Ibrahim proposed a standby mechanism for food security.

These are sensible responses. But Cebu raises a question larger than petroleum or food.

Asean has spent three decades becoming one of the world's most economically connected regions. Much of that success came from connecting its economies efficiently to markets, capital and production networks beyond Southeast Asia.

Recent disruptions have exposed the other side of that achievement: extensive connectivity to the world does not necessarily create the capacity to absorb shocks within the region.

That makes the kind of integration Asean built worth examining.

Its economic strategy followed a successful logic: lower border barriers, attract global capital and plug national economies into world trade. Tariffs fell, investment barriers eased and trade agreements multiplied.

The Asean Economic Community, Asean Trade in Goods Agreement and Regional Comprehensive Economic Partnership reduced barriers to trade and investment across Southeast Asia.

But Asean integrated outward more deeply than it integrated inward.

There are two dimensions of economic integration worth distinguishing. Market-access integration reduces friction so trade and investment move efficiently. Production complementarity goes further: it creates supply chains and industrial relationships in which one country's output becomes structurally important to another's production.

Asean has been more successful at the first. Production integration was always part of its stated ambition but progress has been uneven.

The imbalance is visible in the trade figures. In 2024, intra-Asean trade accounted for about 21% of the region's merchandise trade, compared with roughly 24–25% in the early 2000s. Asean's internal production networks are real but they sit inside an economic system whose trade relationships remain predominantly external.

Two decades of deeper regional integration have therefore not translated into a larger intra-Asean share of merchandise trade. That outcome reflected the political bargain that made Asean integration possible.

Postwar Europe developed stronger supranational institutions, regional transfers and progressively denser industrial interdependence. Asean developed differently. Its postcolonial states placed a premium on sovereignty and policy autonomy.

Governments competed for foreign investment even as they cooperated on trade. Industrial policy remained national. Economic zones were designed primarily to connect domestic production to global capital.

For decades, that bargain worked remarkably well. Asean could integrate economically without requiring governments to surrender much control over their own development strategies.

Globalisation rewarded precisely that model. Multinational firms supplied production networks, foreign markets supplied demand and export-led growth raised incomes across Southeast Asia. But the model also left much of the region's prosperity dependent on networks, markets and supply routes beyond Asean itself.

That dependence matters more as those external networks become more contested. Market access, technology, energy and supply chains increasingly carry geopolitical pressure alongside economic opportunity. Tariffs, export controls and maritime disruption can now travel through the same connections that helped make Asean prosperous.

The energy shock associated with the Strait of Hormuz illustrates one form of this external dependence. Asean members experience it differently according to their resource endowments and fiscal capacity. The region's trade and production architecture reveals a related vulnerability from another direction.

When major overseas markets weaken, Asean exporters remain dependent on purchasing decisions in the United States, China and Europe. Member states may end up competing for shrinking external demand rather than providing alternative markets for one another.

Deeper regional integration would not eliminate these vulnerabilities. Europe's experience after Russia's invasion of Ukraine demonstrated that even highly integrated economies remain exposed to energy and geopolitical shocks.

Geography, fiscal capacity and resource endowments will always matter. But so too does the capacity of a regional system to absorb disruption when it arrives.

Asean increasingly recognises this. The Cebu meetings highlighted energy security, food resilience, stronger regional supply chains and the need to advance the Asean Power Grid. Apsa itself would demonstrate that governments can construct a coordinated emergency framework rather than confront shortages entirely alone.

If ratification is completed before Manila, that deserves to be regarded as an achievement. But emergency coordination and structural resilience are different things.

Apsa can facilitate coordinated mutual assistance during a petroleum shortage. It cannot by itself reduce Asean's dependence on external energy systems.

Food-security arrangements can cushion emergencies without necessarily creating integrated agricultural supply chains or more resilient regional fertiliser production. A power grid becomes transformative when cross-border electricity flows become dependable enough for national systems to incorporate them into routine planning.

That points to the harder stage of Asean integration.

Market-access integration was politically attractive partly because governments could participate while preserving substantial national economic autonomy. Production complementarity asks more.

It requires countries to accept lasting mutual dependence: energy systems that rely on neighbours, industrial strategies built around regional specialisation and supply chains designed partly around Asean demand rather than primarily around customers in Washington, Beijing or Brussels.

No supranational Asean state is required. But governments would have less freedom to optimise national systems as though their neighbours were merely export markets or competitors for investment.

That is why the challenge ahead is deeper than signing another agreement.

For thirty years, Asean's political architecture and economic model fitted each other remarkably well. National autonomy could coexist with increasing market access because globalisation supplied the external demand, capital and production networks that tied the system together.

Manila may show that Asean can build a buffer under pressure. The more consequential question is whether the region can move beyond buffers towards economic relationships in which members become more necessary to one another.

Asean may not have chosen the wrong kind of integration after all. It built the deepest integration its political model could comfortably sustain.

The test now is whether that model can sustain the deeper interdependence that resilience increasingly requires.

Quah Boon Huat is a former sovereign credit rating analyst and policy analyst