China’s response to the U.S. sanctions against the Central Bank of Iran is likely to be an important determinant of the extent to which the United States is successful in weakening the Iranian economy by reducing Iran’s income, especially if other major buyers of Iranian oil curtail their purchases. Eliciting cooperation from Beijing on Iran is challenging for Washington because China’s equities in Iran, views of the efficacy of sanctions, and prioritization of the Iranian nuclear issue on its foreign policy agenda are different from those of Washington. As Washington once again seeks support from Beijing for its efforts to pressure Iran, it is worthwhile to examine recent U.S.-China cooperation on the Iranian nuclear issue and why that cooperation occurred. This essay will detail China’s contributions to the U.S.-led efforts to pressure on Iran in 2010 and explain why the Chinese provided them. It will then highlight some factors that might elicit more cooperation from China on constraining Iran’s nuclear program.