Koki Shigenoi, Associated Researcher at ROLES, published an essay titled “Why Did the U.S.–Iran Agreement Produce the ‘Next War’?: A War over the Text of the Agreement” in Shincho QUE on July 29, 2026.

The essay analyzes how the memorandum of understanding between the United States and Iran did not bring the Iran War to an end, but instead transformed it into a “war over the interpretation of the agreement.” The so-called Islamabad Agreement, reportedly signed by Washington and Tehran in mid-June, established a framework for reopening the Strait of Hormuz and entering a 60-day negotiation period on issues including Iran’s nuclear program. Once implementation began, however, the two sides sharply diverged over the question of who would manage safe passage through the Strait.

The essay argues that the central problem of the Islamabad Agreement was not simply that its wording was ambiguous. Rather, ambiguity was the very condition that made the agreement possible. Tehran interpreted the agreement as a de facto recognition of Iran’s managerial authority over the Strait of Hormuz. Washington, by contrast, read it as imposing an obligation on Iran not to obstruct commercial shipping or restrict passage by force. In this sense, the same text contained two incompatible principles of order.

The essay further argues that the dispute over the Strait of Hormuz can no longer be understood as a simple confrontation between a United States defending freedom of navigation and an Iran seeking to control the Strait. President Donald Trump’s proposal to position the United States as the “guardian” of the Strait and to receive a 20 percent charge on cargo passing through it revealed that Washington itself was moving away from the role of a hegemon that protects freedom of navigation as a free public good. Instead, the United States appeared to be turning into a “fee-charging guardian” that demands compensation for the provision of maritime security.

Against this background, the essay frames the issue not as a binary choice between freedom of navigation and maritime control, but as a question of “dual sovereignty” over the Strait of Hormuz: who manages passage, who guarantees security, who penalizes non-compliant vessels, and who has the authority to extract payment. This does not refer to sovereignty in the strict sense of international law, but to a bundle of quasi-sovereign powers related to passage conditions, security provision, enforcement, and compensation. The Islamabad Agreement did not restore the Strait to an order of free navigation; it brought to the surface competing claims by both the United States and Iran over management, charging rights, and quasi-sovereign authority.

The essay also examines how the conflict has expanded beyond the Strait of Hormuz to the Bab al-Mandeb Strait, the maritime outlet of the Red Sea. The Houthis’ declaration of a maritime blockade against Saudi Arabia and their claimed attacks on Saudi oil tankers in the Red Sea are not treated simply as an extension of the Iran War. Rather, the essay situates them in relation to the Houthis’ own political and military logic, including economic discontent in Houthi-controlled areas, a crisis of governing legitimacy, and the stalled peace process with Saudi Arabia.

At the same time, the essay argues that the Houthis’ autonomous calculations ultimately converged with Iran’s strategic interests. By projecting threats against the Red Sea outlet that could serve as an alternative route to the Strait of Hormuz, the Houthis demonstrated to the United States and the Gulf states that a maritime order excluding Iran could not be sustained. In this respect, the Red Sea crisis externalized local Yemeni dynamics into the broader contest over Middle Eastern maritime order.

The essay concludes that Iran has not become a hegemonic power capable of governing the Middle East. Nor has it acquired the ability to provide a stable order from the Red Sea to the Persian Gulf. In that sense, a stable “Pax Iranica” has not emerged. What Iran is acquiring instead is a different kind of power: not the power to create a regional order, but the power to prevent any order from being established without it. This is not hegemony, but a veto power over regional order.

The essay argues that the Iran War continues not because peace is absent, but because the meaning of peace itself remains contested. The war is not continuing outside the agreement; it is continuing through the ambiguity left inside the text of the agreement.

The full essay is available (in Japanese) below:

[How Long Will the Iran War Last? 5] Why Did the U.S.–Iran Agreement Produce the “Next War”?: A War over the Text of the Agreement
https://que.dailyshincho.jp/node/20196/