In a bold step, President Trump has formally designated Iran’s Revolutionary Guard a terrorist organization — a move that carries serious financial implications for Tehran and lengthy prison terms for those who provide material support.

The move isn’t without risk: Iran has threatened retaliation, including against US forces in the Middle East, which is why Pentagon officials have long opposed the move.

Then again, Iran also threatened massive retaliation after Trump withdrew from the 2015 nuclear deal. Instead, it now faces a collapsing economy (thanks to US-led sanctions) and mounting internal dissent.

Make no mistake about how critical the Guard is to the Iranian regime: It runs Tehran’s ballistic missile program and has long been involved in Iran’s nuclear program.

It exports terrorism (through both financing and troops) and is directly involved in planning and carrying out terror attacks. It is, as Trump said, “the Iranian government’s primary means of directing and implementing its global terrorist campaign.”

Sanctioning the Revolutionary Guard is vital to addressing the key elements that were deliberately omitted from the Obama nuke deal: Iran’s missile program and its fomenting of global terror.

As the president promised, withdrawing from that agreement was just one step in ratcheting up the pressure on Tehran. This is another critical step in that direction.