According to the sources, Hezbollah is moving faster than Iran in its planning and is looking to strike Israel in the coming days.
Iran, meanwhile, appears to still be working out how it plans to respond, multiple officials have told CNN. One US military official told CNN that Iran had made some, but not all, of the preparations that the US would expect to see in advance of a major attack on Israel.
Given Lebanon’s proximity to Israel as its direct neighbor to the north, Hezbollah could act with little to no notice, the second source familiar with the intelligence said, which is not true of Iran.
Iran and Hezbollah have vowed to avenge the elimination of Hamas political bureau chief Ismail Haniyeh in Tehran and of senior Hezbollah commander Fuad Shukr in Beirut.
Israel took responsibility for Shukr's death, but has not commented on Haniyeh's death, though Hamas and Iran were quick to blame Israel.
White House officials on Tuesday said they believe that Iran may be reconsidering its planned attack on Israel, according to Washington Post columnist David Ignatius.
Ignatius wrote that Iran may be "reconsidering a plan for major retaliation" for the elimination of Haniyeh, but the officials stressed that Hezbollah "is still a wild card."
Also on Tuesday, CNN reported that the US is more concerned about Hezbollah's retaliation for the elimination of Shukr than an Iranian retaliation for the elimination of Haniyeh.
An American official and a Western intelligence official told CNN that the US has witnessed Iranian preparations for an attack and believes that the attack will take place in the coming days. However, the form the attack will take is still unknown, as is the level of coordination between Iran and its proxy Hezbollah. Israel National News - Arutz Sheva