In addition to being responsible for much of the worst domestic repression, Iran’s Islamic Revolutionary Guard Corps (IRGC) manages Hizballah and similar terrorist proxies and sends its troops to fight in Iraq, Syria, and elsewhere. On Monday, the White House officially designated the IRGC as a terrorist group—a move, Eli Lake writes, with real consequences:

There is a difference between saying a state is a sponsor of terrorism and calling an arm of a state an actual terrorist organization. . . . The threshold is now lower for proving that someone is providing material support to the IRGC. The designation also makes any non-Iranians who wittingly or unwittingly do business with the IRGC vulnerable to having their U.S. visas revoked. This is [a] powerful disincentive for Europeans [investing] in Iran, . . . because the IRGC’s tentacles reach into most aspects of Iran’s economy.

[T]here are two basic objections to this move. The first is that the designation may provoke Iran to target U.S. forces. . . . Already, Iranian government officials have promised a response to the designation. The mistake is thinking that pressure is any more provocative to Tehran than entreaties. In the days leading up to the final implementation of the nuclear deal in 2016, for example, the IRGC briefly took U.S. sailors hostage and released a humiliating video of the incident after they were released.

The second objection is that the designation further undermines the 2015 nuclear deal. A progressive group chaired by alumni of the Obama administration made this point; however, some see this objection as a point in the Trump administration’s favor. “It makes it much more difficult for a Democratic president to go back into the Iran deal in 2021,” says the Iran-sanctions expert Mark Dubowitz, who favors the designation. Any future administration would have to make [an official] determination that the IRGC was out of the terrorism business [before removing the sanctions].

Determining that the IRGC is no longer engaged in terrorism is about as likely as determining that the IRS is no longer engaged in collecting taxes. It’s in the organization’s nature. . . . Donald Trump’s strategy, unlike his predecessor’s, begins with the premise that Iran is an outlaw state—and treats it as such until it changes its behavior.