The war between the United States and Iran began as a regional confrontation with global economic consequences. It could remain that way, but the situation also contains a far darker possibility: as in 1914, a series of individually rational decisions by world powers could lead to international catastrophe.

Unresolved flash points current and potential—Ukraine, the Gulf, Yemen, Lebanon and Taiwan—could begin reinforcing one another until every major power finds itself committed to multiple fronts simultaneously. The global tension could reshape the calculations of Russia, China, Europe and the United States in ways that trigger interlocking escalation.

A Stalemate the World Cannot Accept

Suppose the present stalemate continues. The Strait of Hormuz—and America’s Gulf allies—remain subject to repeated Iranian harassment. Iran’s Houthis proxies disrupt traffic through the Bab el-Mandeb, placing both access points to the Arabian Peninsula under persistent pressure. America continues responding with intermittent strikes against Iranian military assets and proxy forces while insisting that diplomacy remains possible. Tehran continues demanding the right to control tax shipping through Hormuz.

Meanwhile, the global economic consequences stack up. The world's energy markets depend upon the uninterrupted flow of oil and liquefied natural gas through the Persian Gulf. The Red Sea remains one of the principal arteries connecting Europe and Asia. Every week of disruption increases insurance premiums, extends shipping routes, raises transportation costs and feeds global inflation. Fertilizer markets tighten, aviation fuel becomes more expensive and supply chains collapse.

To restore freedom of navigation, military planners begin examining how greater pressure can be applied not only to Iran itself, but to the network through which it projects power across the region.

The Houthis present the most immediate problem. For more than a decade, Saudi Arabia tried and failed to defeat them, and Riyadh has little appetite for restarting that war alone. Yet so long as the Houthis retain the ability to close the Bab el-Mandeb, they can threaten one of the world’s principal commercial arteries, cripple traffic through the Suez Canal and deprive Egypt of desperately needed hard currency. They must be somehow crushed.

Hezbollah presents a parallel opportunity in Lebanon. Syria joins efforts to sever Iran's supply routes and military infrastructure, while the Lebanese state moves against Hezbollah from within. What had long been treated as an Israeli problem is recast as an effort to restore Lebanese sovereignty.

The Popular Mobilization Forces then turn Iraq into a third front. As Iranian-backed militias intensify attacks on American facilities, Kurdish forces and coalition supply lines, Washington reinforces its presence in Iraqi Kurdistan to protect coalition operations, strengthen the Kurds and preserve the ability to strike the PMF throughout Iraq. Iraq once again becomes an arena.

NATO is now on side. The U.S., with NATO backing, has seized Kharg Island, Iran’s critical oil depot, and Qeshm Island, central to its control of Hormuz. Neither operation produces Iranian capitulation or restores free passage through the Gulf.

Iran is protected by mountains, immense distances and limited avenues of approach, but its regional network is increasingly exposed. The coalition may still insist that it is not pursuing regime change. Tehran, Beijing and Moscow see the U.S. assembling the military architecture for just that.

The Counter-Coalition Forms

That transforms the strategic calculations of every major power.

Russia, China and North Korea recognize that they share a common strategic interest: none wishes to see the Iranian regime collapse under American military pressure, with the U.S. emerging from the Gulf with enhanced influence over one of the world's most important energy corridors. All recognize that a prolonged conflict consumes military resources, industrial production and political attention that Washington might devote elsewhere.

Beijing need not send combat divisions. It can expand deliveries of dual-use electronics, industrial equipment, drones, missile technologies, satellite support, financial assistance and intelligence while shielding Iran diplomatically from efforts at the UN Security Council to legitimize wider military action. The objective is to ensure that America cannot achieve a decisive outcome at acceptable cost. China is now openly a U.S. military rival.

For Moscow, the military partnership already forged with Tehran during the Ukraine war deepens further as Russia expands deliveries of air-defense systems, electronic warfare capabilities, intelligence, advisers and advanced military technologies. Every additional month that the United States remains preoccupied in the Gulf improves Moscow's strategic position in Ukraine, and toward Europe.

North Korea fits in naturally, having already demonstrated its willingness to exchange artillery ammunition, ballistic missiles and manpower for Russian economic assistance and advanced military technology. So China, Russia, Iran and North Korea begin acting as a loose strategic coalition—an Axis—whose members support one another because each benefits from exhausting the military and political capacity of the U.S. and its allies.

The Wars Begin to Merge

The longer the Middle Eastern crisis persists, the more attractive it becomes for rival powers to exploit Washington's distraction.

Ukraine has stabilized the front and developed the ability to strike deep into Russia's military economy. Long-range drone attacks increasingly damage oil infrastructure, defense production and other strategic targets, turning Russia's vast geography into a military liability. Yet the widening Middle Eastern war imposes a severe cost on Kyiv. American and allied stocks of air-defense interceptors, precision-guided munitions and long-range missiles are increasingly diverted to protecting the Gulf and Red Sea, leaving fewer available for Ukraine. Putin responds with intensified missile and drone attacks, supplemented by North Korean ballistic missiles, calculating that Kyiv's dwindling interceptor stocks leave it increasingly exposed. Ukraine, concluding that the conflicts can no longer be separated, expands operations against Iranian assets supporting Moscow's war effort.

For the first time, success or failure in one theater begins directly affecting the military balance in another.

The Kremlin sees its opportunity. After more than four years of attrition, an America increasingly committed to the Persian Gulf —and a Europe whose arsenals are stretched across multiple theaters—offers the best chance yet to alter the balance. Russia launches its largest offensive since the opening months of the invasion while increasing pressure along NATO's eastern frontier through Belarus and Kaliningrad. If Ukraine appears close to collapse, European governments conclude that arms deliveries are no longer enough. Air-defense units, engineers, intelligence assets and eventually combat troops begin deploying into Ukraine under one coalition or another. Open confrontation between Russia and European members of NATO follows.

China, meanwhile, sees its own opportunity. A maritime blockade or escalating military coercion against Taiwan tests American resolve while placing enormous economic pressure on the island. Washington cannot stand aside. Major American naval and air forces surge into the western Pacific alongside Japanese and Australian support. Resources urgently needed in Europe and the Middle East now compete with equally urgent demands in East Asia.

The Wars Become One

Europe is fighting Russia over the future of Ukraine and the security of NATO's eastern frontier. The United States and Japan are attempting to prevent the forcible absorption of Taiwan while maintaining freedom of navigation across the western Pacific. American and coalition forces remain deeply engaged in the Middle East, attempting to reopen the Strait of Hormuz and the Red Sea while containing Iran and its network of regional proxies. North Korea supports Russia, China sustains Iran, and the Arab governments increasingly align with the Western coalition because their own economies depend upon restoring maritime commerce.

Israel occupies an unusual place within that coalition, militarily indispensable because of its intelligence, technology and operational experience, yet politically uncomfortable for all (that may diminish if Netanyahu is ousted in the fall).

And the conflict extends far beyond the battlefields. Cyber attacks disrupt financial systems, ports, electrical grids and communications infrastructure. Intelligence agencies wage an increasingly aggressive covert war involving sabotage, espionage and influence operations across every continent. The distinction between the battlefield and the home front steadily dissolves as governments mobilize economic, technological and financial resources on a scale unseen in generations.

Terrorist attacks against American, European or allied targets become increasingly likely as Iran's regional strategy expands beyond the Middle East and sympathetic extremist networks seek opportunities to impose political costs on the coalition. Whether those attacks are directed by governments, encouraged through proxy organizations or simply inspired by the broader conflict matters little politically. Public opinion throughout the democratic world begins demanding stronger retaliation, broader military operations and more ambitious political objectives. A big enough attack could cause hysteria.

Talk of nuclear weapons is no longer taboo.

A war that began as an effort to restore freedom of navigation in the Persian Gulf would have become the catalyst for a global strategic contest stretching from the Red Sea to Eastern Europe and the western Pacific. None of the major powers would have set out to fight a world war. Each would simply have pursued what appeared to be rational responses to immediate crises.

It does not have to happen this way. A comprehensive blockade of Iran may yet prove preferable to an open-ended regional war. Whatever strategy policymakers ultimately choose, they should abandon the comforting assumption that today's flash points can remain separate. History suggests that world wars are less often the product of grand design than of crises that gradually become impossible to disentangle.

Dan Perry is the former London-based Europe-Africa Editor and Cairo-based Middle East Editor of The Associated Press, chairman of the Foreign Press Association in Jerusalem and the author of two books.

The views expressed in this article are the writer’s own.