For three decades after the Cold War, Washington operated under a dangerous assumption: that military supremacy could indefinitely compensate for diplomatic exhaustion.

The United States possessed the world's most advanced armed forces, unmatched naval reach, and a financial system capable of weaponizing sanctions against adversaries thousands of miles away. From the Balkans to Baghdad, this power often created the appearance of control. But appearances in geopolitics have a short shelf life.

The latest confrontation with Iran has exposed something American policymakers have resisted admitting for years. The age of uncontested US primacy is ending — not because America has suddenly become weak, but because the structure of global power has changed faster than Washington's strategic imagination.

What makes this realization especially painful is that the erosion of American leverage has not primarily been imposed by enemies. Rather, much of it has been self-inflicted. Great powers, history shows, rarely collapse from a single defeat.

They decline by confusing military capacity with strategic wisdom. Imperial Britain learned this after Suez in 1956. The Soviet Union learned it in Afghanistan. The US now risks learning the same lesson in the Persian Gulf.

The Iran confrontation is demonstrating a striking paradox. America can still inflict enormous damage, yet it struggles to achieve decisive political outcomes. That distinction matters because military victories are tactical events while political victories define history.

Why endless pressure produced diminishing returns

Washington's Iran policy has oscillated between coercion and fantasy. One administration tears up agreements in pursuit of "maximum pressure."

Another attempts partial diplomacy while maintaining the architecture of sanctions. Then comes another round of threats, military deployments, cyber operations and economic restrictions. But Washington's underlying assumption never changes: eventually, Tehran will break under pressure.

Yet states under sustained pressure often adapt instead of surrender. Iran's survival strategy resembles what smaller powers throughout history have done when confronting stronger adversaries. Vietnam did it against the US.