President Trump’s decision to designate Iran’s Islamic Revolutionary Guard as a terrorist group is a long overdue step that will help put the squeeze on one of the leading drivers of instability in the Middle East.

The IRGC is a special branch of Iran’s armed forces that exists to protect the regime’s Islamic government and its global interests. Over the decades, IRGC has helped to squash internal dissent, built up terrorist groups abroad (especially Hezbollah), helped oversee the nuclear program, and played a destabilizing force through proxies in Iraq, Syria, and Yemen.