The Trump administration has notified Israel that it plans to submit a formal request at the UN Security Council on Thursday to initiate "snapback" sanctions on Iran, Israeli officials tell me.

Why it matters: This move could create a diplomatic and legal crisis unlike any seen before at the Security Council. It comes days after the U.S. failed to mobilize support at the council to extend an international arms embargo on Iran.

The big picture: Despite having withdrawn from the 2015 Iran nuclear deal, the U.S. is invoking its terms in an attempt to force sanctions lifted under the pact to snap back into place.

• The deal says any of the signatories — the U.S., Russia, China, France, Germany and the U.K. — can demand sanctions be reimposed automatically if they believe Iran has committed substantial violations. No country can veto such a move.
• Russia and China contend that the U.S. gave up its right to reimpose the sanctions when it withdrew from the deal. That view is shared by others on the council, and even by John Bolton, the hawkish former national security adviser.
• The U.S., on the other hand, claims it has the right to initiate the snapback mechanism because it is a party to the Security Council resolution which endorsed the nuclear deal, and included the snapback mechanism.
• The European signatories, who have tried desperately to save the nuclear deal, also oppose the U.S. move.

How it works: Secretary of State Mike Pompeo is expected to arrive in New York on Thursday and present formal letters to the UN secretary general and the UN ambassador from Indonesia, which holds the Security Council's rotating presidency.

• The letter will then be circulated to other members, beginning a 30-day consultation period.

What to watch: Israeli officials and Western diplomats both say they expect a major diplomatic crisis over those 30 days.

• If any member of the Security Council submits a resolution to stop the snapback move, the U.S. will be able to veto it.
• U.S. officials believe that the renewal of international sanctions will lead Iran to withdraw from the nuclear deal — and likely make it impossible for Democratic nominee Joe Biden to put the deal back together if he wins the November.
• Israeli officials were notified on Monday that the Trump administration intended to submit the official complaint on Thursday.