Governments across Asia are racing to build up oil reserves and to speed renewable energy projects in response to the war involving Iran. The fighting has renewed fears about tanker traffic through the Strait of Hormuz, the chokepoint that carries a large share of the world's crude. Buyers in the region have been adding cargoes and filling storage tanks at a faster clip to guard against interruption. Higher freight and insurance costs since the conflict began have added to the strain on import-dependent economies. Energy security has also become the stated reason to accelerate solar and wind construction in several capitals. Japan, South Korea and India, all heavy oil importers, have the most to lose if supplies tighten further. How long the war runs will decide whether the current stockpiling stays temporary or becomes a lasting change in how Asia buys energy.