The U.S.-Israeli war against Iran has fractured the Iranian government, complicating its ability to make decisions and coordinate larger retaliatory attacks, according to officials familiar with U.S. and Western intelligence assessments.

Several dozen Iranian leaders and their deputies have been killed since the war began four weeks ago. Those who survive have had difficulty communicating and are unable to meet in person, for fear of having their calls intercepted by the United States or Israel and being targeted in an airstrike.

While Iran’s security and military agencies continue to function, the government’s ability to plan new strategies or policies has been weakened.

The Trump administration has said a new government is in charge in Iran and has pressed it to make a quick deal. But the more degraded Iranian government decision making becomes, the more difficult it will be for it to negotiate with American envoys or make significant concessions.

With different leaders in place, Iranian negotiators may have little knowledge about what their government is willing to concede, or even whom precisely to ask.