JEFFREY BROWN: And we return to the bloody civil war in Syria.
Today, U.S. Sen. John McCain became the highest-ranking American official to enter Syria since the start of fighting there. He crossed the Turkish border accompanied by a Free Syrian Army general.
Meanwhile, a fierce battle continues in the strategically critical town of Qusayr, with Hezbollah sending fighters from its home base in Lebanon to support the regime of Syrian President Assad. And, yesterday, two rockets exploded in an area of Beirut controlled by Hezbollah. That raised new concerns about the spread of the Syrian conflict into the larger region.
Margaret Warner is in Beirut. And we spoke earlier today.
Margaret, let's begin with those rocket attacks in southern Beirut. How much is known about who might be behind them, and why now in these Hezbollah-controlled areas?
MARGARET WARNER: Well, since this is Lebanon, Jeff, the land of many conspiracy theories, there are a lot of conspiracy theories about this, from that it's forces allied with the Sunni rebels in Syria who are upset about what Hassan Nasrallah, the Hezbollah leader, vowed on Saturday, that Hezbollah is going to fight on the side of Syria to the end, to -- that is, to the Syrian regime -- to, you know, there are other people in the street who will say it's the Israelis.
One person who has talked to investigators said they are looking hard at a radical Sunni faction, a couple of them, in Palestinian camps that have been here for very long time. And there are some groups that are thought to be allied with either al-Qaida or the Al-Nusra Front, which is the jihadi rebel group in Syria.
It is going to be very hard to tell, however. I was -- diplomatic sources told me today that the .107-millimeter rockets were set on detonators and timers, so that the perpetrators could be long gone. They went from an uninhabited area in the hills.
But everyone, whatever their theory here, agrees that it was a response to what Hassan Nasrallah said on Saturday and to the presence and growing presence of Hezbollah fighters on -- in Syria fighting on the side of Bashar Assad.
JEFFREY BROWN: And that being Lebanon, as you said, with all of its history, what has been the reaction and how much particularly vis-a-vis raising old conflicts, old tensions, sectarian tensions?
MARGARET WARNER: Well, exactly, Jeff.
This is a country divided among Sunnis, Shias and Christians. They had a bloody, bitter civil war for 15 years that ended in 1990. And they ended up with a fragile, sort of cobbled-together political system that everyone gets a little share. But the tensions remain.
And the new dividing line really is, are you for or against Assad, the Assad regime? Hezbollah and most Shias do support the Assad regime. Most Sunnis support the opposition. The Christians are split. And the fear here is that, as people said to me on the street, you know, this could reopen -- the -- the tensions are already there, that it could really inflate them, incite them.
They have had fighting, of course, in Tripoli, as you know, between Alawite and Sunni factions there on different sides of the Syria conflict, and also in the Bekaa Valley. This is the first time there's been any blowback in the capital, Beirut.
JEFFREY BROWN: Now, we have mentioned this speech on Saturday by the Hezbollah leader, Hassan Nasrallah. In fact, Hezbollah's support for the Assad government in Syria has become ever more important in this conflict, right?
MARGARET WARNER: Right, Jeff.
At first, Hezbollah leadership kept saying, well, these are just popular committees of committed Shia who don't like what's going on in Syria. But Saturday, Nasrallah -- we were at this speech, which he didn't actually show up. It's a big television screen in front of some 60,000 people in the Bekaa Valley.
But he made it clear that it's official Hezbollah militia policy that they are going to stay in this fight until they feel they have assured that Assad is going to hold on to power. It is -- where they're fighting is a very important corridor. It sort of hugs the Lebanese border. It's the corridor that links Damascus to the coast.
And though the coast isn't entirely Alawite, which is Assad's Shia sect, it is the area that is believed to be sort of Assad's plan B. He's lost control of a lot of country, but that's the area where it's believed he would try to consolidate power and then perhaps go back and retake areas.
But this corridor all along the Lebanese border is very important. And Hezbollah fighters are over there. No one knows for sure, but I heard from fighters, rebel fighters on the ground who had come into Lebanon yesterday that there are thousands of them.
JEFFREY BROWN: And this includes, Margaret, that battle that's ongoing right now and is considered quite a key one in Qusayr.
MARGARET WARNER: Yes.
The town of Qusayr is key in that corridor. It's on the Damascus highway to the city of Homs and to the coast. And what the Free Syrian Army, the sort of moderate resistance, has been doing is using areas in Lebanon to, say, bring their families to safety if they can get out.
We talked to a couple of fighters who had done exactly that yesterday. They said they are -- the rebels have held that town for quite a while. But they are being pounded and pounded from the air, that it's really hollowed out, but there are still probably tens of thousands of civilians there. I said to this young man, how are they surviving? He said, well, we have dug some shelters under the buildings that remain.
But this is where Assad has turned the tide, in the area around Qusayr. And these people are getting -- are really getting cut off. I did ask, how did he know? He said most of the fighters that they do see on ground from the Assad forces are Hezbollah. And I said, how do you know? And he said, well, first of all, they have uniforms, but they have M-16 rifles, he said. Not even the Syrian army has M-16s. They have Kalashnikovs.
And he said they wear these uniforms, they cover their faces and there's just no doubt they're Hezbollah.
JEFFREY BROWN: All right, well, Margaret Warner in Beirut, take care. And we will look for your reporting in the days to come. Thanks so much.
MARGARET WARNER: Thanks, Jeff.
GWEN IFILL: Late today, British Foreign Secretary William Hague announced the European Union talks on Syria failed to reach an agreement, effectively lifting the ban on arming the rebels. He says Britain has no immediate plans to ship them weapons.