Koki Shigenoi, Visiting Researcher at ROLES, published an essay titled “The United States’ Narrowing Options and the Growing Possibility of a Protracted War of Attrition” in Foresight on April 3, 2026.

The essay analyzes how the United States’ strategic options in the Iran War are becoming increasingly constrained, and how the conflict may be shifting from a short, decisive campaign toward a protracted war of attrition. It argues that the core of Washington’s ceasefire proposal lies in weakening Iran’s postwar deterrent capabilities, including its nuclear and missile programs, proxy networks, and influence over the Strait of Hormuz. By contrast, Tehran’s central objective is to secure political and strategic guarantees that it will not be attacked again.

The essay emphasizes that U.S.–Iran ceasefire negotiations are stalled not simply because the two sides differ over the level of concessions required, but because each side rejects the other’s desired end state. The United States cannot end the war without substantially reducing Iran’s deterrent capacity, while Iran cannot accept an end to the war that leaves it without deterrence and regime-security guarantees. In this sense, the essay argues, what is now unfolding is not merely negotiation toward a ceasefire, but a war over the terms on which a ceasefire itself will be defined.

The essay also examines the ammunition and fiscal constraints facing the United States and Israel. It points out that the tempo of the war is beginning to outpace the speed at which critical munitions can be replenished, making it increasingly difficult to sustain both long-range strike operations and missile defense. As a result, Washington is left with three broad options: escalation in pursuit of a quick decision, a unilateral declaration of ceasefire or victory, or a continuation of the status quo. Yet each of these options may fail to end the war and instead deepen the conflict’s drift toward a prolonged war of attrition.

A central focus of the essay is Iran’s emerging practice of “selective control” over the Strait of Hormuz. Tehran’s objective is not necessarily to impose a total blockade, but to determine who may pass, under what conditions, and at what cost. In this way, the Strait of Hormuz is becoming more than a maritime chokepoint. It is turning into a strategic lever through which Iran can externalize the costs of war onto the global economy and alter the calculations of the United States, Israel, and the Gulf states.

The essay concludes that the Iran War cannot be understood solely through the question of when it will end. The more important question is what will break first: the military and fiscal endurance of the United States and Israel, Iran’s ability to exercise selective control over the Strait of Hormuz, or the current structure of the war itself as Gulf states and the wider international community become more directly involved in the management of maritime traffic. The war may not end simply because one side declares victory. Rather, it may continue in altered form as an era of selective control inscribed into the Strait of Hormuz and the global economy.

The full essay is available (in Japanese) below:

[How Long Will the Iran War Last? 3] The United States’ Narrowing Options and the Growing Possibility of a Protracted War of Attrition
https://que.dailyshincho.jp/node/17230/