Second, Israel could attack Hezbollah or lure it into a war to destroy capabilities that threaten Israel's security. Israel could also decide to degrade Hezbollah’s capabilities in order to deny Iran a "second-strike" capability should Israel decide to attack Iran's nuclear facilities. Israel could also use a conflict with Hezbollah as the catalyst and cover for an attack against Iran's nuclear facilities. Any of these circumstances could persuade Israel that a preventive military strike against Hezbollah is in its interest.

Of the two scenarios, the second is the more likely.

Hezbollah is near the top of America’s list of most dangerous terrorist organizations. If the next Israeli-Hezbollah confrontation were to result in a sharp decline in Hezbollah’s military capabilities and was not accompanied by substantial civilian casualties or destruction of Lebanon’s civilian infrastructure, the result would be beneficial for U.S. interests. However, [the possibility of] such an outcome is slim. The more likely unfolding of an Israeli-Hezbollah war would hold almost no positive consequences for the United States, which is focused on three Middle East priorities: trying to slow or stop Iran's nuclear program, withdrawing combat troops from Iraq, and helping Middle East peace talks succeed. Although the United States has essentially backed Israeli claims of Scud deliveries to Hezbollah, an Israeli attack, however efficient or successful, would arouse the Arab "street" and complicate the efforts of moderate Arab governments to support U.S. objectives in the region.

While Syria is unlikely to respond militarily to an Israeli attack against Hezbollah, it could resume its support for Iraqi insurgents to attack U.S. forces in Iraq. Syria would likely calculate that the United States would not retaliate against its support of Iraqi insurgents, but rather blame Israel for the increased danger to U.S. forces in the region.

The Middle East peace negotiations likely would enter another deep freeze. As in past military confrontations in Lebanon, Palestinians would find it impossible to keep negotiating as Arabs are fighting Israel in Lebanon. [my emphasis]