For decades, the Arab rulers of the Gulf have lived inside a fantasy — one in which their skyscrapers, oil wealth and American alliances somehow guarantee their dominance of the region. But the future of the Arabian Gulf will not belong to them. It will belong to Iran. And not because Iran is loved, admired or embraced, but because power follows gravity, and in the Gulf, every form of strategic gravity tilts toward Tehran.

Iran’s rise is not a matter of opinion. It is the logical outcome of geography, demography, military capability, ideological reach and the accelerating decline of the Gulf monarchies. Iran does not need to conquer the region. It simply needs to outlast it. And outlast it will.

Start with geography. Iran controls the northern coastline of the Gulf and sits over the Strait of Hormuz, the world’s most important oil chokepoint. A single Iranian decision can raise global energy prices, shake international markets and terrify every Gulf capital simultaneously. No amount of wealth or PR campaigns can change the map. The monarchies are trapped by geography; Iran is empowered by it.

The monarchies are trapped by geography; Iran is empowered by it.

Then consider the political structures of the Gulf states — wealthy, glittering and hollow. They rely on expatriate labor for everything from construction to medical care. Their militaries depend on foreign officers, foreign maintenance crews and foreign cybersecurity. Their most prized jets and missile systems cannot be operated without Western contractors. This is not sovereignty. This is rented power. And rented power dissolves the moment the landlord leaves.

Iran, by contrast, has depth — territorial, demographic and ideological. Nearly 90 million people, countless militias and allies across the Arab world, and an entire state apparatus built for endurance. It has withstood sanctions, war, isolation, covert attacks, assassinations and economic collapse. Yet it remains intact and defiant. No Gulf state has ever endured even a fraction of that pressure. They would crumble in months.

Worse for them, Iran has mastered asymmetric warfare while the Gulf monarchies have mastered shopping. Tehran invests in drones, missiles, proxies, cyber tools and regional networks that can strike at multiple fronts simultaneously. The Gulf invests in grand museums, luxury islands and weapons it cannot operate. Iran can destabilize any one of its neighbors at will. None of the Gulf states can destabilize Iran. The asymmetry is absolute.

And then there is the slow, painful fact Gulf rulers refuse to confront: the United States is leaving. Not suddenly, not theatrically but inevitably. Washington’s priorities are shifting to China and the Pacific. The Gulf is no longer central to global energy. The political appetite for defending monarchies that offer little in return is evaporating. Once American protection thins, the Gulf monarchies will find themselves exposed, militarily weak and painfully aware of the neighbor across the water who has been preparing for this vacuum for decades.

When the U.S. steps back, Iran will step forward — not because it invades, but because it becomes the only state with real strategic weight. Iran will dictate the tempo of regional diplomacy. It will influence oil pricing indirectly by controlling the risk environment. It will shape what conflicts ignite or cool. It will have a voice — loud and unavoidable — in Bahrain’s internal politics, Iraq’s governance, eastern Saudi Arabia’s unrest and Oman’s balancing act.

Iran will dictate the tempo of regional diplomacy.

Iran’s dominance will not look like empire. It will look like suffocation. Gulf states will still fly their flags and host their conferences, but every major decision — security, oil flow, foreign alignment — will silently account for Iran’s reaction. Tehran won’t need to rule the Gulf. It only needs the Gulf to fear it more than anyone else. And that reality is already visible.

The Gulf rulers understand this privately, even if their public rhetoric denies it. They know Iran is patient, ideological and structurally resilient. They know they cannot fight Iran directly. They know their survival depends on avoiding a confrontation they cannot win. That silent understanding is the seed of Iran’s future control.

Over the next two decades, the Gulf will shift from defiance to accommodation. Not because they want to, but because they must. The U.S. will be less reliable. Energy markets will continue to change. Internal pressures — from economic transitions to demographic imbalances — will weaken the monarchies from within. In that environment, Iran becomes the unavoidable center of gravity. Its influence will stretch across the water, across the oil terminals, across the political systems of its neighbors, and across the future of the region.

In the end, the idea that the Arab Gulf states will forever resist Iranian dominance is a myth sustained only by American military power. Once that power fades, reality will hit like a tide: Iran has the population, the geography, the military innovation, the ideological networks and the patience to shape the region. The Gulf monarchies have none of these.

The future of the Arabian Gulf will not be determined by wealth, glamour or imported security. It will be determined by power—and power, in this region, belongs to Iran.

– Jamal I. Bittar is a university professor and opinion writer focused on Middle East politics and U.S. foreign policy. He is based in Toledo, Ohio. The views expressed are solely his own and do not represent those of any institution with which he is affiliated.