Security officials in Israel closely monitored the "day of rage" Tuesday in Lebanon amid fears that the political violence could spill over into a new conflagration with Israel.
As hundreds of protesters took to the streets of Lebanon to protest the naming of a Hezbollah-backed politician as prime minister, Israel beefed up security along its northern border.
Since the 2006 Second Lebanon War, tensions have remained high between Israel and Hezbollah, a militant group that operates in southern Lebanon close to the Israeli border.
Hezbollah has issued numerous statements calling for the destruction of Israel -- while Israeli officials have repeatedly called Hezbollah a terrorist organization that poses a "direct threat to the Jewish State."
This week's selection of Hezbollah-backed Prime Minister Najib Mikati was seen as a victory for the Shiite group, while followers loyal to outgoing Prime Minister Saad Hariri, a U.S. ally, took to the streets to protest.
But those demonstrations were small and fractured, and Mikati seemed to have cobbled together enough support within the political system to assume power.
In Israel, politicians warned that the new Hezbollah government took it farther into the arms of extremist Islamic regimes and away from its Western alliances.
Faced with the potential shift of Lebanon's fragile power balance away from the United States and toward Iran-backed Hezbollah, Secretary of State Hillary Rodham Clinton suggested U.S. aid and support could be at risk.
"A Hezbollah-controlled government would clearly have an impact on our bilateral relationship with Lebanon," Clinton said in Washington. The U.S. government considers Hezbollah a terrorist organization.
Along Israel's northern border, intelligence officials have increased surveillance of Lebanon.
Israeli intelligence officers told McClatchy Newspapers that they have long believed that political turmoil in Lebanon over the findings of the Hariri tribunal -- a U.N. investigation into the 2005 assassination of former Lebanese Prime Minister Rafik Hariri -- could spill over into clashes with Israel.
During a briefing at a lookout point on Israel's northern border, an intelligence officer gave a detailed picture of Hezbollah's preparations for a confrontation with Israel. She acknowledged, as well, that Israel was "gearing many resources," to prepare for a clash with Hezbollah.