Rodela Romero was attending an event at her church in northern Manila when her phone rang. It was a local reporter asking her to comment on what was being described to her as a nightmare scenario.

Ms. Romero, who oversees the oil industry at the Philippine Department of Energy, had been following news of the U.S.-Israeli strikes on Iran that day in late February. Now, the reporter told Ms. Romero, the Strait of Hormuz — the vital maritime choke point through which the Philippines imports enormous amounts of crude oil — had been shut.

“We import almost 100 percent of our petroleum products,” said Ms. Romero, 64. “We’re so vulnerable,” she recalled thinking at the time.

In the ensuing weeks, government officials scrambled to secure supply from alternative producers, at great cost. Gasoline prices doubled and diesel prices tripled, triggering transit strikes in Manila and a sudden spike in inflation that experts warned could push more than a million Filipinos into poverty.

On March 24, President Ferdinand Marcos Jr. declared a national energy emergency. The Philippines was the first country to take such a step, highlighting the view that, outside the Middle East, the economic effects of the U.S.-Iran war are primarily a crisis for Asia.

Developing nations across Asia have been hit hard by the monthslong throttling of energy flows because of their deep reliance on Middle Eastern oil and gas. As clashes between the United States and Iran ramp up again, and shipping traffic in the Persian Gulf nears a halt, regional capitals in Asia are assessing how to prepare for a future of protracted instability.

The Philippines is leading what is expected to be a wave of developing nations seeking to build strategic petroleum reserves — stockpiles of crude oil that can be tapped during disruptions. Japan is offering financing and technical expertise, and officials in Tokyo say they are holding similar talks with Indonesia, Thailand and Vietnam.

Japan’s involvement is part of an effort to bolster its regional energy security, according to Taro Han, a former official at Japan’s trade ministry, who recently joined The Asia Group, a consulting firm. Even with its own substantial stockpiles, Japan remains deeply dependent on Southeast Asian supply chains for goods made with oil byproducts, including medical supplies.

Just as the 1970s oil shocks transformed the global energy architecture — spurring 16 of the world’s largest economies to establish the International Energy Agency, which requires member states to hold a 90-day cushion of net oil imports — a similar structural shift is underway today.

The question is whether, as electrification and renewable energy proliferate, it is the right time for a wave of fast-growing, energy-hungry countries to commit hundreds of millions of dollars to amass fossil-fuel reserves.

Over the past five decades, the maintenance and periodic deployment of these reserves have helped stabilize global supply and prices. In March, the I.E.A. set off the largest coordinated release in its history to help steady oil markets after the outbreak of fighting in the Middle East.

Yet the release had a muted impact on economies in Asia that are heavily dependent on Persian Gulf imports but don’t have national strategic reserves. In the Philippines, the first and most dramatic effects were felt by drivers who faced soaring fuel costs.

“The impact on drivers’ incomes has been huge,” said Mody Floranda, the national president of Piston, a labor coalition representing drivers of jeepneys — the flamboyant, chrome-plated utility vehicles that zigzag along the streets of Manila. Jeepney drivers charge a base fare of about 13 pesos, or 21 U.S. cents, to ferry passengers who hop onto the open backs of their vehicles.

Mr. Floranda, 60, was speaking from the group’s headquarters in Manila, a wood-paneled room littered with megaphones, cardboard sardine boxes and protest signs calling for economic relief and an end to “the U.S. war of aggression.”

He said that the daily wage needed to support a family of five in the Philippines was estimated to be around 1,200 pesos, or $20, but given the current fuel prices, a driver who works 12 to 18 hours a day takes home only about 400 to 600 pesos. “This is obviously not enough,” he said.

In April, Piston filed a petition to raise fares by 10 pesos per ride to reflect higher diesel prices. The group is awaiting official government approval. “Ten pesos does not affect income that much,” Mr. Floranda said. “It’s merely to survive the high price of oil.”

The Philippine Institute for Development Studies, a state-run think tank, warned in a report in April that crude prices of around $105 a barrel could push more than 1.3 million Filipinos into poverty. Global oil prices rose above that level in the early stages of the war, and though they have recently traded lower, at around $90 a barrel, an uptick in fighting has incited renewed volatility.

While the acute-phase supply panic appears to have subsided, the economic damage is lingering as higher fuel costs bleed through the economy, inflating the price of everything, including food. “The impacts on poverty, welfare and growth are still unfolding,” said Adoracion Navarro, a senior research fellow at P.I.D.S.

The Asian Development Bank expects rising commodity costs to drag down growth. In a report released this month, the bank lowered its growth forecast for developing economies in Asia and the Pacific to 4.9 percent in 2026, a slowdown from 5.5 percent growth in 2025.

Recent A.D.B. board meetings have been dominated by discussion about how best to support the Philippines and other developing Asian countries particularly vulnerable to oil-supply disruptions. Officials have debated whether to help countries build emergency stockpiles or accelerate the transition away from oil.

Strategic petroleum stockpiles are expensive and time-consuming undertakings. Building a 90-day reserve is expected to cost nearly half a billion dollars for the Philippines. Crude oil also has a shelf life in storage, meaning that costs are ongoing.

Albert Park, the A.D.B.’s Manila-based chief economist, said he was cautious about recommending support for stockpiling oil.

“If you have an option to just scale up renewable energy and reduce dependence, that’s another way to build resilience,” he said. “Not to say you shouldn’t do it, but you’d better have a clearheaded understanding of the costs and benefits of that strategy because it’s expensive.”

Mr. Han, the former Japanese trade ministry official, said that Tokyo was advocating reserves that meet the I.E.A. benchmark of 90 days’ worth of demand. “We need a more long-term, comprehensive approach in order to strengthen our energy security in the region,” he said. Helping Asia build up reserves “is at the very core of our diplomacy at this particular moment,” he said.

At the Philippine Institute for Development Studies, Ms. Navarro thinks the answer is to build a modest level of strategic reserves, while also pushing for investments in energy efficiency, electric vehicle charging infrastructure and Manila’s skeletal rail networks.

“A 90-day reserve is a lot of money,” she said. “It’s I.E.A. levels, and we’re not yet an economically advanced country.”

The legislature in Manila is still conducting hearings on how to codify a strategic petroleum reserve policy into law. The Department of Energy is also looking into how to encourage the construction of more refineries, so that the Philippines will have the capacity to turn crude reserves into refined products like gasoline and diesel, according to Ms. Romero, the department official.

That was another vulnerability exposed recently, when China halted exports of refined petroleum products in March. It was a big blow to the Philippines, which relies on China’s diesel supplies.

In her office, tucked away in the back of a sun-bleached compound in Manila, Ms. Romero recounted when she received the news of China cutting off exports via another call from a local reporter.

That time she wasn’t at church. “Otherwise, I would have just prayed,” she said. “Prayed for a miracle.”