Iranian leaders continue to insist that any agreement with the United States must include a cessation of hostilities between Israel and Hezbollah as well, but the fighting between them threatens to derail the whole peace process.

While the U.S. and Israel went to war against Iran on Feb. 28, Hezbollah, one of Iran’s top proxy forces in the region, resumed attacks on Israel days later, and now, with the U.S. and Iran on the verge of a deal that could pave the way to long-term stability, the fighting between Israel and Hezbollah could collapse the whole deal before it comes to fruition.