What do you do when there are no good guys? Pick the least bad, I guess.
France says that it is to speed up the delivery of weapons to the Lebanese army, as violence from Syria's conflict threatens to spill over.
The army has been fighting and Islamist militants from Syria for days around the eastern border town of Arsal.
A 24-hour ceasefire was agreed between the two sides, but reports say the truce collapsed within three hours when an army position came under fire.
Fighting began on Saturday when Syrian rebels raided the mainly Sunni town.
They objected to the detention by Lebanese forces of an alleged member of Syria's Islamist militant group al-Nusra Front.
At least 17 soldiers have been killed in the area since the weekend, with 22 more reported missing.
The "humanitarian ceasefire" which started at 19:00 local time (16:00 GMT) would allow time to investigate the fate of the missing soldiers and to evacuate the casualties, an unnamed security source told Reuters.
"Clashes erupted but now they have ended. The ceasefire is still on, it did not collapse. What happened was to be expected due to differences between the fighters," he said.
Read more: http://www.bbc.co.uk/news/world-middle-east-28657223