Why Lebanon Matters to Israel

Lebanon has the dubious honor of being a perfect, if unwilling, host for Middle Eastern proxy battles. Two developments will shape Israeli-Lebanese relations:

• Will Israel attack Iran? If Israel attacks Iran, expect Iran's allies in Lebanon to join in the fray. If it doesn't attack Iran, Israel could settle for giving Iran a bloody nose in Lebanon instead.

• Will the uprising in Syria descend into civil war? If Syria, Israel's chief Arab nemesis and an ally of Iran, descends into chaos, it could drag Lebanon down with it and Israel would again be hard-tested to just sit back and watch.

Israel's Strategic Objectives in Lebanon

1. Containing Syria

   Squeezed between Syria and Israel, Lebanon has a weak state, and deep political and religious divisions that are easy to manipulate. For outside players, it's just too tempting. Everyone that's someone in the Middle East sets up shop in Beirut.

   The trouble for Israel is that for the last three decades it's mostly been Syrians running the show in Beirut. Since their failed invasion of Lebanon in 1982, the Israelis have grudgingly accepted a Syrian hand in Lebanon, but drew a red line under Syrian heavy weaponry inside the country.

   And here it gets complicated. Syria instead chose to increase its own deterrent power by facilitating the generous flow of weapons from Iran to Hezbollah - a Lebanese Shiite militia turned political party that is deeply hostile to Israel.

2. Neutralizing Hezbollah's Threat

   Hezbollah is not only the most powerful militia in the country, over which the Lebanese state has no control. It's one of the few forces in the region capable both of launching cross-border operations and offering fierce resistance to an Israeli ground attack.

   Watching Iran use Lebanon as a linchpin for hostile operations is untenable for Israel. Its 2006 attack on Hezbollah failed to significantly reduce the group's capabilities, and Israeli Defense Force (IDF) has been itching for a re-match ever since.

What to Watch For

1. Iran's nuclear program

   Iran is believed to be well-prepared for an asymmetrical response to an Israeli attack on its nuclear facilities. While Iran's Palestinian allies seem to be drifting away from Tehran, Hezbollah might back its patron by unleashing a rain of rockets on northern Israel.

   This would in turn almost certainly provoke heavy Israeli bombardment, not only of the militia's positions, but also targeting the military and civilian infrastructure of the Lebanese state.

   In the words of a senior Israeli defense analyst: "People won't be going to the beach in Beirut while Haifa residents are in shelters." You better take him seriously.

2. Civil war in Syria

   But if you are looking for a proper nightmare scenario, think about this. Lebanese parties are perhaps evenly split between allies of the Syrian president Bashar al-Assad, such as Hezbollah, and those opposed to Syria's role, who normally look to Saudi Arabia and the West for support.

   The anti-Syrian camp will be emboldened by Assad's weakening power, leading to rising tension and a possible repeat of 2008 clashes between rival militias. Weapons for Hezbollah's adversaries would be provided by Saudi Arabia, a super-wealthy Sunni power embroiled in a regional struggle with the Shiite Iran, creating a potential for a wider conflict.

   In this situation, Israel may sense a perfect opportunity to deliver a knock-out punch at Hezbollah.

   Read more on the impact of Syrian uprising on Lebanon.

So, listen tightly to the news from Damascus and Tehran. The louder the drumbeats of war between Israel and Iran, and the deeper the slide toward civil war in Syria, the more we'll be nervously looking at Lebanon.