If Washington’s participation in Israel’s June 2025 war with Iran elevated U.S. military force to a perfectly viable instrument of the United States’ Iran policy, the success of current talks would signal the formal undoing of that logic. But should the failure of talks pave the way for another full-scale war, the United States and Israel will be fighting an Iran vastly different from June. For the Iran of today appears to have made its peace with the grim conclusion that while a decisive slog with Israel and the United States is sure to be agonizing, it is preferable to the recurring attrition of repeated wars and a chronic strategic vulnerability that only emboldens adversaries to target Iran and its regional allies.



https://quincyinst.org/research/right-sizing-the-russian-threat-to-europe/
That’s an argument, not proof.