US intelligence assessments before Israel escalated its conflict against Hezbollah in September wrongly predicted catastrophic outcomes, with hundreds or thousands of Israeli casualties. However, Israel's military achievements in Lebanon were overwhelming, as the IDF dismantled Hezbollah's military infrastructure and killed and wounded thousands of operatives. The assessments from the American intelligence community relied heavily on Israel's own assessments. The US officials stressed that both countries were concerned about the severity of a full-blown war with Hezbollah, but Israel believed the cost was necessary. The US eventually shifted its position to back Israel as the IDF's airstrikes against Hezbollah's rocket and weapon depots fundamentally changed the assessment of the war's trajectory.