“This wasn’t a little dust-up, this was some serious fighting,” said a foreign adviser to the Lebanese army. He requested anonymity, as he was not authorized to speak to the media.

Instead of staging a hit-and-run assault typical of previous ISIL attacks, this time the fighters attempted to hold the hilltop. But that exposed them to the Lebanese army’s artillery and air power. The adviser said that the fighters “ended up getting slaughtered,” and that the army “roasted” the hilltop with artillery, then went to “pick up the smoking remains.”

Eight Lebanese soldiers died in the battle, and the bodies of 47 fighters were recovered.

Lebanon has long lived in Syria’s shadow and faces increasing spillover from the war tearing apart its larger, more powerful neighbor. In the first half of 2014, suicide car bombers struck multiple times in Shia areas of Lebanon, killing dozens of people in attacks claimed by Sunni groups.

ISIL has imposed a self-declared “caliphate” across a vast stretch of northern Iraq and northeastern Syria, gaining international notoriety for its brutality. The latest example was the videotaped immolation of Moath al Kassasbeh, a Jordanian fighter pilot whose plane crashed in Syria in December.

The threat posed by fighters in the mountains straddling the border has led to an intensified debate in Beirut’s political and diplomatic circles about the possibility of requesting military assistance from the international Arab coalition assembled last year to destroy ISIL.

However, the Lebanese government is unlikely to formally request coalition airstrikes in eastern Lebanon due to the opposition of the powerful Hezbollah. Hezbollah fighters, who run a chain of lofty defensive outposts along the eastern border, have clashed with fighters from ISIL and Jabhat al-Nusra while defending a string of Shia villages in the eastern Bekaa Valley. But last September, Hezbollah leader Sheikh Hassan Nasrallah rejected the newly created international alliance against ISIL, “whether it targets the Syrian regime, Daesh or others.” He accused the United States of being the “source of terrorism in the world” and ethically unqualified to lead a “war against terrorism.”

“It’s a sensitive issue,” said Basem Shabb, a Lebanese lawmaker who sits on the parliamentary defense committee. “I don’t think the government is going to approve [a request to the international coalition]. I think the Americans are aware of that, and they are not going to be raising the issue.”

Instead the U.S. is helping the Lebanese army help themselves through the provision of weapons systems, ammunition, training and equipment. In the past year alone, the U.S. has provided $120 million in military assistance. The latest equipment to arrive was dozens of armored Humvees and M109 self-propelled 155 mm artillery guns.