Each side is betting it can last longer than the other, analysts say. But there are risks in a stalemate without a deal.

The journalist, Shelly Kittleson, was abducted by a militia allied with Iran and held for a week. Iraqi officials say she was freed in exchange for the release of militia members.

Some residents described the strikes overnight Monday into Tuesday as among the worst they had experienced since the war started.

Many in Iran feel helpless in the face of their entrenched system, and some are becoming increasingly embittered by the fierce American and Israeli bombardment.

Iranian state media reported that the country’s top clerics have identified who will replace Ayatollah Ali Khamenei. They have not released his name.

The U.S. and Israel have pounded Iran’s leadership and undercut its defense capabilities, but President Trump has offered wildly different explanations for what he hopes to achieve.

The C.I.A. has given small weapons to Iranian Kurdish forces in Iraq in a covert program that began before the current war.