U.S. and Israeli intelligence have learned of an ongoing debate in the Iranian leadership. The more radical leaders, who control the Revolutionary Guard, and the al Quds force, want to equip Hamas (in Gaza) and Hezbollah (in southern Lebanon) with more lethal weapons, and goad Israel into another war. The Iranian radicals have been trying to get anti-aircraft and anti-tank missiles to Hamas, as these weapons can be used immediately against Israeli helicopters, F-16s and UAVs that regularly operate over Gaza, and the armored vehicles that come in with raids and patrol the security fence. So far, none of these weapons have gotten through. The Israeli air raid on Sudan last January destroyed nearly twenty truckloads of these weapons. Iranian cargo ships are being watched closely for additional attempts to get the missiles to Gaza. This effort could backfire badly. There's a risk that, if Iranian anti-aircraft and anti-tank missiles get used in Gaza, the Israelis may decide that their decision to leave Gaza four years ago was a big mistake, and take control once more.
A more worrisome effort is to supply Hezbollah with chemical warheads for some of their rockets. The less radical Iranian clerics have blocked this proposal, so far. The majority of the clerics who run the religious dictatorship in Iran are reluctant to see chemical weapons used on Israel, as they fear the retaliation (which might include a nuke, as the Israelis have no chemical weapons of their own). The more radical clerics take the "God is on our side" angle more literally and believe Israel can be taken down if hit hard enough. A little nerve gas should do it. The Iranian clerics usually work out compromises in cases like this, and the deal may include shipping chemical warheads to Hezbollah, but keeping them under the control of the Iranian security officers stationed there. Many Hezbollah leaders are also not keen on employing the chemical option. That's because Israel has the ability to take all of southern Lebanon, and grind Hezbollah into the dust. The Israelis would take a lot of casualties. But if Hezbollah hit Israeli civilians with mustard or nerve gas, the Israeli troops would have plenty of incentive to come across the border with murderous intent.