The long-awaited agreement between the United States and Iran does not settle their disputes, but the alternative is a war with devastating human and economic consequences.

ran sits astride one of the world's most important energy chokepoints. The story centers on Iran, the United States, and the nations whose economies depend on uninterrupted oil flows through the Persian Gulf.

Officials in Tehran got the United States to sign a document that even Americans described as degrading, mortifying, a total capitulation.

The past year may resemble a circle in US-Iranian relations leading back to the same place, but the trajectory has spiraled downwards, for the US and the region as a whole.

The Iran crisis became a test of American power in one of the world's most volatile regions. It involved Washington, Tehran, Israel, and a wider Middle East shaped by decades of rivalry, deterrence, and strategic competition.

In March, the American president promised that “There will be no deal with Iran except UNCONDITIONAL SURRENDER!... IRAN WILL HAVE A GREAT FUTURE.” He didn’t clarify that it would be the United States that would do the surrendering.

Tehran has learned it can survive the worst Washington can throw at it, but it still needs sanctions relief to stave off economic calamity.

Iran has come out of the war's first chapter stronger than many expected, but its next challenge may be harder, the BBC Persian Service's Amir Azimi writes.