Mearsheimer Doubts Israel Could Defeat Iran Alone

John Mearsheimer, the University of Chicago political scientist and leading proponent of offensive realism, has told audiences that he finds it unlikely Israel could defeat Iran in a war fought without the United States. The remark, circulated in clips by Iranian outlets, carries a pointed logic: Israel did not achieve victory against Iran even with American support, so, in his framing, it is hard to see how it would do so alone.

In one clip carried by Fars News Agency, Mearsheimer said Israel would absorb “heavy blows” from Iran in any solo attack ^[1]. The same argument appeared in a version run by Akharinkhabar ^[2]. Neither outlet has published the full interview, and Iranian state-affiliated media have an obvious interest in amplifying a scholar who argues that Washington has failed in its confrontation with Tehran. The core claim should be weighed on its own merits rather than on its distribution.

The argument is not new for Mearsheimer. His earlier work has consistently argued that the United States overextends itself in the Middle East and that regional powers should carry more of the burden. What is notable in these remarks is the extension of that thesis: the military question matters less than the economic one. He has argued that military options against Iran do not work and that Washington’s only effective lever is economic pressure. He has also argued that Iran is pressing the US and global economies through the Houthi-Saudi confrontation in Yemen, which he presents as a source of cost for Washington ^[1][2]. A separate report in The New Arab, titled “Iran war is defeat for US, John Mearsheimer tells Arab Centre,” framed his position as a judgment that the conflict amounts to an American setback ^[3].

That framing deserves scrutiny. Mearsheimer’s view that Israel cannot win alone rests on an assessment of Iranian retaliatory capacity, including missile and proxy networks spanning Lebanon, Yemen, Iraq and Syria. Those networks are real. Yet the argument reads the 2025-2026 period as evidence that Iranian deterrence has held, when a more contested reading is available. Iran’s proxies have suffered sustained losses, and the Islamic Republic’s regional position has narrowed. Mearsheimer’s critics, including Francis Fukuyama, have argued that realism of this kind underweights the costs of abandonment and the stabilizing role of sustained US commitments ^[4]. That critique applies here. If Washington signals that Israel must fend for itself, it does not reduce the probability of confrontation; it raises the incentive for Iran and its partners to test the limits of deterrence.

The Lebanon dimension is revealing. In a separate clip, Mearsheimer reportedly suggested that Iran should find a way to press Washington into forcing Israel out of southern Lebanon through an agreement ^[5][6]. That is a remarkable prescription from a scholar who presents himself as an analyst rather than an advocate: it treats an active confrontation with Hezbollah, a designated terrorist organization, as a bargaining chip for Tehran to trade. Israeli northern residents who have lived under rocket fire for much of the past two years would reasonably see it differently.

For regional observers, the more useful signal is what Mearsheimer’s remarks reveal about the debate inside Washington and beyond. The argument that the United States cannot credibly defend Gulf states, and that Iran can impose economic costs through the Red Sea and Gulf of Oman, is now being made openly by respected Western voices. Gulf governments, particularly in Riyadh and Abu Dhabi, have taken note. Whether Washington’s partners conclude that they must hedge against US retrenchment, or that they must build deterrence of their own, will shape the next phase of regional alignment far more than any single academic’s assessment.