Since March 1978, when Israeli forces invaded Lebanon in what was known as Operation Litani, the United Nations Interim Force has been deployed in South Lebanon. It never succeeded in completing its mandate, namely ensuring the Lebanese government extended its sovereignty to the Israeli border. Since May 2000, when Israel pulled out of Lebanon, the obstacle has been Hezbollah, which has created a state within a state in the border area -- as well as Beirut's southern suburbs and the northern Beqaa Valley.

That failure should not detract from the fact that only an international presence along the Israeli-Lebanese border, in conjunction with the Lebanese Army, could realistically guarantee the security of Lebanon's southern population, but also that of Israel's north. Until last week, Hezbollah claimed it alone could provide such security, but the ongoing Israeli onslaught has shown that claim to be a sham. Lebanon's southerners would probably welcome an international presence, but as long as it is a UN force, preferably an expanded UNIFIL, which is popular in the south, not a NATO force.

The hard part is making sure that such a project is preceded by the military neutralization of Hezbollah. No force will step in and act as a buffer between Hezbollah and Israel if both sides a ready to resume their conflict.

Several ingredients would help make such a plan work: Hezbollah must be weakened so it cannot oppose an international force and later rearm behind the peacekeepers' back; the southern Lebanese must approve of the force, though Hezbollah might try to discredit it; Russians must be brought in, making it more difficult for Iran to oppose the plan; international reconstruction investment must enter the south, to prevent Iranian money from flooding in and buying undue influence that can be turned against the peacekeepers; and Israel must formally guarantee that it will not violate Lebanese sovereignty. It must also withdraw from the disputed Shebaa Farms region, and engage in a prisoner deal exchanging its Lebanese prisoners for the two Israeli soldiers abducted by Hezbollah last week -- but this must be run through the Lebanese government, not Hezbollah.

Such steps would make it more difficult for Hezbollah to oppose any arrangement, because all the plan's stated goals -- Israeli guarantees, a withdrawal from Shebaa, prisoner releases, security for the south, are supposedly the party's bread and butter issues. Such a force might remain for some time, but it would be worth it if it neutralizes the Lebanese-Israeli border, and returns both sides to their 1949 Armistice Agreement.