Pressure can work on Iran. There has been, for more than a decade, a curious line of argument that pressure upon Iran is counterproductive.
Iran and the United States are as close to direct conflict as they have been for three decades, since Operation Praying Mantis in 1988 which was, at the time, the largest surface naval engagement since World War II.
A lot of ink has been spilled and oxygen expended discussing the matter, some of it good and some of it simplistic. Here a few thoughts, informed by being lucky enough to spend close to seven months studying in the Islamic Republic while finishing a doctorate in philosophy on Iranian history. I worked on the Iran desk at the Pentagon during the George W. Bush administration, frequently visit the Persian Gulf, and have followed Iran almost continuously for a quarter century.