This UN force is struggling to help keep the peace in southern Lebanon. So why is it still there?

As Lt. Col Jordan Hertzberg watches black smoke rise beyond a ridge moments after Israeli artillery fires into southern Lebanon, he tells CBC News that he believes Israel's offensive could have been avoided, if the UN peacekeepers stationed along the 120 kilometres border were doing their job. 

"If they had been enforcing the mandate, we would not have a war today," said Hertzberg who is originally from Montreal.

"When we find bases, Hezbollah bases, 50 metres, and 75 metres from a UN base, what is your observation? You have to be blind and deaf not to be aware of that."

When Israel and Hezbollah ended their war in 2006 by agreeing to a UN-proposed ceasefire, the resolution included the enlargement of the UN peacekeeping force that had already been stationed in southern Lebanon for decades.

But as war has broken out again, the 10,000 plus UN Interim Force in Lebanon (UNIFIL) has not only been unable to quell the conflict, it has also found itself in the middle of it. The peacekeepers are being attacked by Israel, which is accusing them of just being in the way.  

UNIFIL's mandate is to help enforce UN Resolution 1701 that was adopted in 2006. That includes aiding the Lebanese armed forces in clearing the area south of the Litani river in Lebanon of "any armed personnel, assets and weapons." This area is about 30 kilometres south of the Blue Line, which was set by the UN in 2000 to confirm the withdrawal of Israeli forces.

But UNIFIL says that without co-operation from the Lebanese government or its armed forces, it's challenging to fulfil that mandate. Meanwhile, others have criticized UNIFIL's efforts and some observers are questioning whether it does or can play any kind of peacekeeping role in the region and whether its mandate should be renewed.

The Israel Defence Forces says it has found stashes of ammunition and rockets, along with bunkers dug into the ground close to where UNIFIL is stationed. 

During a trip to the border area in the northwest of Israel on Thursday, Hertzberg accused the UN peacekeeping mission of turning a blind eye, which allowed Hezabollah to deeply entrench itself in the south of Lebanon, and enabled it to launch rockets into northern Israel throughout the past year.

"UNIFIL has proven ineffective in carrying out its mission for decades now, and absent significant changes, there is little hope it can play a relevant role in securing the Israel-Lebanon frontier," read a recent analysis by the Washington Institute for Near East Policy.

"Should the force continue to under perform, Washington should once again seriously consider vetoing its mandate, ending the deployment, and starting anew."

The analysis placed blame on the Lebanese government and armed forces for both collaborating with Hezbollah while also obstructing UNIFIL's access to areas they want to inspect. The analysis also blames UNIFIL itself, saying it "often demurs from effectively monitoring areas that might generate tension" and "pulls punches in its reporting."

UNIFIL has accused Israel of repeatedly targeting its positions, an accusation Israeli Prime Minister Benjamin Netanyahu has denied.

Earlier this month, he repeated a call for UNIFIL to withdraw from combat zones and said the military did its utmost to avoid harming peacekeeping personnel while striking Hezbollah fighters.