The new lines of southern Lebanon

The U.N. peacekeepers' armored vehicle moves slowly along the de facto border in southern Lebanon, not because of the terrain or the threat of shelling and drones, but because every mile means relearning a landscape profoundly transformed by war.

UNIFIL — the United Nations Interim Force in Lebanon — has been monitoring this area since 1978, when it was created to verify Israel's troop withdrawal after its first occupation of Lebanon.

The U.N. expanded UNIFIL's mandate 20 years ago to include monitoring adherence to a ceasefire in fighting between Israel and Lebanon's Iran-backed Hezbollah - the militant group created in 1982 to counter a second Israeli invasion.

Almost half a century later, the peacekeeping force's mandate will expire at the end of the year and due to U.S. and Israeli opposition, will not be renewed. There is still no durable ceasefire.