By threatening hydrocarbon supply routes, tensions around the Strait of Hormuz are pushing the United States, Europe and China to accelerate their energy sovereignty, each in its own way.

For decades, the Strait of Hormuz has embodied one of the world’s greatest energy vulnerabilities. At its narrowest point, this maritime chokepoint between Iran and Oman is barely 40 kilometres wide, yet it carries about a quarter of global seaborne oil trade, according to the International Energy Agency. From the tanker attacks in 2019 to the tensions intensified by the war in Gaza, energy markets have been operating under constant strain: with every episode, oil prices spike sharply, reviving the same scenario — a global oil shock. But as crises keep recurring, another question is coming to the fore. Could these tensions, indirectly, become a driver of the global energy transition? The issue is no longer just the price of oil, but uncertainty. Major energy agencies have documented this shift since the war in Ukraine: states are now seeking not so much cheap energy as predictable and sovereign energy. This change in paradigm directly benefits renewables: a solar plant or a wind farm depends neither on a strategic strait, nor on a military fleet, nor on an oil cartel.

The United States present a more mixed picture. Thanks to shale oil and gas, they have become the world’s largest producer of hydrocarbons, which reduces their direct vulnerability to Hormuz without fully insulating them from crises. Oil remains a global market, so any conflict in the Persian Gulf pushes up prices for American consumers, with immediate political consequences. Under the Biden administration, this reality led to repositioning the energy transition as a national security tool as much as a climate one: the Inflation Reduction Act, signed in August 2022, mobilised some $370 billion for low-carbon technologies. Since Donald Trump’s return to the White House in January 2025, several of these funding streams have been suspended or called into question — without the entire structure collapsing: because a large share of the industrial investment generated by the IRA landed in Republican states, Congress has proved more cautious than expected in the face of calls for repeal.

China, however, remains the most exposed player. As the world’s largest oil importer, Beijing is structurally dependent on the Persian Gulf: together with India, it absorbs nearly half of the volumes transiting through Hormuz, according to the IEA. Beijing identified this vulnerability long ago, and it has shaped its strategy in depth. On one side, a massive diversification of supply sources: Russia has become China’s largest oil supplier since 2022, supplemented by purchases from Africa and through overland pipelines that bypass vulnerable sea routes. On the other, unprecedented investment in renewables, less out of climate conviction than as a security calculation. China’s total renewable capacity now exceeds 2,340 GW, representing more than 60% of the country’s installed power capacity. China produces 80% of the world’s solar panels and dominates the battery supply chain. Each gigawatt installed reduces, marginally but durably, its dependence on straits.

The paradox remains, however: geopolitical crises can also produce the opposite effect. In the short term, they often encourage greater exploitation of hydrocarbons; after the invasion of Ukraine, several European countries restarted coal-fired plants, while American oil majors posted record profits. Conflicts simultaneously accelerate the search for alternatives and the immediate use of fossil fuels. The American case illustrates the same ambivalence: on his return to the White House, Donald Trump issued several decrees aimed at reviving hydrocarbon production and suspending certain climate-related funding. The retreat is real, but it runs up against a reality Trump had not anticipated: as many green investments are now anchored in Republican constituencies, lawmakers from his own camp have slowed the most radical attempts at dismantling them.

The energy transition is therefore advancing not only under the effect of climate awareness. It is also moving forward under the pressure of crises, strategic rivalries and economic vulnerabilities. Washington, Brussels and Beijing are following different paths — legislative tools, supplier diversification, industrial dominance in green value chains — yet converging on the same imperative: no longer relying on a strait that no one truly controls. In this new global balance, Hormuz is playing an unexpected role: that of an unintended accelerator of the very transition it is meant to threaten.

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