if the agreement between the united states and iran calls for a unilateral withdrawal of israel from lebanon without a subsequent withdrawal of hezbollah from lebanon, that would be a non-starter and something israel could not abide by. so long as hezbollah is in lebanon, israel will also be in lebanon. the agreement would need to call for a bilateral withdrawal, and the withdrawal would need to be carried out reciprocally, or it's a non-starter and it won't be abided by.