Former U.S. national security officials faced off Monday over the U.S. designation of Iran’s Islamic Revolutionary Guard Corps (IRGC) as a foreign-terror organization.

The IRGC, a paramilitary force that reports to the country’s Supreme Leader, is already under several rounds of U.S. sanctions; anyone found doing business with it is subject to secondary sanctions. But the move has significant diplomatic consequences. The IRGC is Iran’s “primary means of directing and implementing its global terrorist campaign,” President Donald Trump said in a statement.

Trump said the designation significantly expands “scope and scale of our maximum pressure campaign on the Iran regime,” crystalizing the risks of doing business with the IRGC. “If you are doing business with the IRGC, you will be bankrolling terrorism,” he said in the statement.