For decades, much of Southeast Asia has operated on an implicit bargain: the United States provides a security umbrella, while the region preserves its strategic autonomy. The current war in the Middle East should make Southeast Asian governments reconsider whether that bargain is sustainable.
The lesson is not that the United States should leave Southeast Asia. Nor is it that American military power has no value. Quite the opposite. American intelligence, naval power, air power and extended deterrence remain important components of the regional security architecture.
But the war in the Middle East has exposed two uncomfortable truths. First, America's security commitments are ultimately contingent on American interests.
When war broke out between the United States, Israel and Iran in February this year, the consequences impacted beyond the three actors.
Iran retaliated against US military bases and other targets across the Gulf. Tehran's disruptions in the Strait of Hormuz pushed energy prices higher and threatened supplies that Asian economies depend on.
Southeast Asia, heavily dependent on Middle Eastern oil and gas, was immediately exposed. A paper published by the ISEAS – Yusof Ishak Institute has estimated that some regional countries have only 30 to 100 days of oil reserves.
However, the strategic lesson extends beyond energy security.
The United States has enormous military resources, but those resources are not infinite. The Middle East has demonstrated how quickly American forces can be drawn into another theatre and how military assets can be redeployed when circumstances change.
Under the Trump administration, Washington moved US military assets from Asia to the Gulf region during the conflict. In March this year, the Americans redeployed the terminal high-altitude area defence (THAAD) missile-defence system from South Korea to the Middle East. At the same time, more than 2,200 US Marine personnel based in Okinawa, Japan, were redeployed to the war zone in the Middle East. Further eroding American military presence in Asia, Washington redeployed the carrier USS George Washington from the Pacific to the Middle East in August, leaving the Pacific region without an American aircraft carrier.
There is another major issue: American stocks of precision-guided munitions were depleted. That inevitably raises questions about how much capacity Washington would retain for a simultaneous crisis in the Indo-Pacific.
For Southeast Asian governments, this should prompt a simple question: what happens if the American military is needed in two places at once?
That question is particularly relevant given the region's growing dependence on US security partnerships. The Philippines has deepened its defence relationship with Washington, while Singapore provides US forces access to its military facilities. The US is a key military exercise partner for regional states.
These arrangements have obvious benefits. But dependence comes at a cost. The more a state’s security architecture relies on another power's military capabilities, the more exposed it is to that power's changing priorities.
Second, hosting American military forces can provide security while also exposing a state to a wider conflict.
A foreign military presence can deter an adversary. But it can also make the host state part of a conflict over which it has little control.
The Gulf provides the clearest illustration. American military facilities in the region were not simply instruments of deterrence; during the current war, they became targets for Iranian retaliation.
That does not mean Southeast Asian countries should close existing facilities or end military cooperation with Washington. But it also means governments should be much more explicit about the risks that accompany an American military presence.
If a conflict involving the United States and China were to erupt over Taiwan or elsewhere in the Western Pacific, what would happen to facilities that support US operations? Would they remain outside the conflict? Would the host government have control over how they were used? Would the presence of American forces make the Philippines and Singapore more secure, or in a worst-case scenario, make them a target?
These are hypothetical questions that should be part of the strategic debate now.
The central lesson of the Middle East war is not to allow another state's military power to become the only thing standing between Southeast Asia and insecurity.
Perhaps the answer is greater self-reliance in collective defence, the economic domain, resilient supply chains, adequate stockpiles of fuel and critical materials, stronger cyber defences, and the ability to protect infrastructure without automatically depending on an external power. It should also mean strengthening ASEAN's crisis-management capacity.
Ultimately, Southeast Asian states must retain enough capabilities and relationships of their own to prevent any one external power from becoming indispensable.
That may be the most important security lesson the Middle East offers Southeast Asia.
