FOR those of us in Southeast Asia, developments in the Middle East can feel geographically remote. Yet whenever tensions rise between the United States and Iran, the effects ripple far beyond the Persian Gulf. Southeast Asia’s prosperity depends on stable energy supplies, secure maritime routes and a predictable global economic order — which is why the latest US-Iran peace agreement may prove more consequential for this region than many initially appreciate. The agreement is best understood as a framework rather than a final settlement. But it has meaningfully reduced the risk of wider conflict. The reopening of maritime routes, the...