"Iranian officials have cautioned their Gulf counterparts that they will widen their targets if attacked again—perhaps to include Bahrain, home to America’s Fifth Fleet. Such threats may be just bluster. An Iranian attack that caused real damage in the Gulf would probably trigger an enormous American response. Then again, if the Islamic Republic felt existential peril from a mix of domestic protests and foreign attacks, it might take the gamble. In any event, Gulf rulers have no desire to call its bluff.
They also worry about what comes next. They have spent most of this century dealing with the consequences of state collapse in Iraq, after the American-led invasion, and then in Syria, during a long civil war. Unrest in those countries sent everything from jihadists to amphetamines flowing into Jordan and the Gulf. The Saudis also have a civil war in neighbouring Yemen to worry about, and another across the Red Sea in Sudan.
The last thing they want is state collapse in Iran, a country of 92m people just 200km across the water. Refugees are one concern. Weapons are another: a fragmented Iran might lose control over its arsenal of missiles and drones, to say nothing of the thousands of kilograms of uranium still unaccounted for after the war.
There is no love lost between Arab regimes and the Islamic Republic. The former would welcome a new Iranian government that was willing to curtail its nuclear programme and its support for Arab militias. After two years of regional war, however, many Middle Eastern governments now fear that unrest in Iran will lead to more chaos rather than less."