The Battle Over Snapback Sanctions

The U.S. notified the United Nations Security Council on Thursday that it would impose “snapback” sanctions on Iran for its failure to comply with the 2015 nuclear deal. The move will trigger a battle at the U.N., but the U.S. has the right to act.

Barack Obama and John Kerry designed the nuclear accord to go through the U.N. because the U.S. Senate would never ratify a treaty with terms so favorable to Tehran. If Mr. Obama wanted the deal to last, he should have negotiated something acceptable to Capitol Hill. Instead,…