"We are worried about this and watching very closely," a Hezbollah ground commander said this week. "We know they will be coming here now."
Hezbollah, according to the commander, has plans in place for such attacks, including a security plan to close off Shiite neighborhoods from the rest of the city. It also has a formidable intelligence service already tasked with watching for Iraq veterans trying to illegally enter from Syria.
But while such groups have received little support from Lebanon's Sunnis in the past, their humiliating defeat last week by Hezbollah and the tensions that led to the clashes already had Beirut's urbane and unarmed Sunni population looking to religious conservatives and rougher men from outlying regions like Tripoli, Akkar, and the Bekaa Valley, which all have significant militant communities.
"We know that the Future Movement has been working with some groups and that new groups have been forming in Tripoli," one top security official not cleared to speak to the media said early this year. "These groups have similar ideas to al Qaeda and can offer weapons and training to the Sunnis here. We are also seeing support from some Saudi princes concerned about Iran's influence."
Are they sending jihadist fighters? "We're not sure yet, but these are the same people who have sent them in the past," he said. "I'm not sure the country could take this new threat. It's already so weak."
The nearly perfect conditions for an al Qaeda-like outbreak of violence in Lebanon have not been missed by the group's senior leadership. On April 22, al Qaeda No. 2 Ayman al-Zawahiri suggested the Middle East's most liberal and diverse nation could play an important role in the ongoing conflict with the West. "Lebanon is a Muslim frontline fort," he said. "It will have a pivotal role, God willing, in future battles with the Crusaders and the Jews.
"I call upon the jihadist generation in Lebanon to prepare to reach Palestine and to banish the invading Crusader forces which are claimed to be peacekeeping forces in Lebanon," he said, in reference to the United Nations peacekeepers on Lebanon's southern border with Israel.