The Khomeinist regime survives by causing crises and tensions. It is the same pattern that it formed when it’s “Muslim Student Followers of the Imam's Line” invaded and took armed siege of the U.S. embassy compound, holding its staff hostage.
Soon after it created that crisis, the regime guaranteed a hold on its governance by entering an eight-year war with its western neighbor, Iraq. They pushed the war forward with an anti-Semitic slogan: "The Road to Jerusalem Goes through Baghdad."
By stoking fears through propaganda, the regime replaces each crisis with the next. It is true that the sanctions strangle the economy, and so also become a crisis. But the economic pressure of sanctions could also help the people bring down the regime, and so put an end to the crisis cycle that the regime counts on to stay in power.
The Khomeinist regime, which has come under domestic political-economic pressure ever since it took power in 1979, has called for unity among the people to face down the international pressures against it. The regime propagandizes those external pressure of sanctions to offset the internal crisis it faces from Iran’s people. Sanctions become an excuse to crack down on the anti-government uprisings.
Western allies must coordinate sanctions efforts in a continuous manner, if they really want sanctions to bring regime change in Iran, or to even change the behavior of the regime.
Meanwhile, the Iranian people’s protests should be openly supported as well. The resistance movements are in urgent need of leadership gathered under the umbrella of a trusted and beloved figure. That should become one of a combination of serious and all-out measures, including maximum sanctions pressure, which together would certainly lead the regime to collapse.