Israel and Hezbollah agreed Friday to halt fighting in southern Lebanon after days of escalating clashes threatened to derail the fragile US-Iran peace process, reducing the risk that the first major test of the U.S.-Iran agreement would turn into its first major failure.

Experts says that any continuation of conflict in Lebanon is the biggest threat to deal.

Israel and Hezbollah have agreed to a ceasefire that is scheduled to take effect on Friday, according to a senior United States official, marking a potentially significant step…