(CBS News) HERMEL, Lebanon - The momentum is shifting in Syria's two-year-old civil war. The Assad dictatorship is now gaining the upper hand over the rebels, thanks to help from Hezbollah, a militant group based in Lebanon.
Monday, the European Uniona terrorist group and the White House applauded the move.
Western journalists rarely get to see how Hezbollah operates. But CBS News recently spent time with the group along the Syria-Lebanon border.
In recent months, the militant Shiite Muslim group has thrown its support behind Syria's President Bashar Assad. Fighting alongside the Syrian army, Hezbollah has helped them to win key victories against the Syrian rebels.
A secretive group, Hezbollah gave CBS News rare permission to travel to its stronghold of Hermel, on the Syrian border.
We were escorted by a Hezbollah guide who did not want to show his face. He said that the group only joined Syria's civil war after Syrian rebels fired more than a hundred rockets across the border.
"The rebels are the ones who transgressed against this land," he said. "Hezbollah is defending its own people."
The border between Syria and Lebanon is so porous, it's easy for Hezbollah to move back and forth.
Hezbollah fighters have been working closely with the Syrian army to try to secure an entire corridor along the Lebanese border and in doing so cut off vital rebel supply lines.
When CBS News climbed onto a rooftop, we could see a Syrian army checkpoint only a hundred yards away.
Hermel's Deputy Mayor Essam Bleybel said that Hezbollah's ties to the Syrian regime run deep.
"The backbone of Hezbollah is the Syrian regime," he said. "They supported us with guns and gave us all kinds of help. We won't leave the people who helped us behind."
But since Hezbollah has joined Syria's war, the fighting has spilled over the border to Lebanon.
Bleybel said it's a sacrifice he is willing to make, and he is willing to support Hezbollah at any cost.
For Lebanon, the stakes are high. This country fought its own civil war for 17 years. Now, many fear that their small, deeply divided nation could be consumed again -- this time by Syria's war next door.