The Syrian war may be entering its final phase. Rebel fighters, from various factions, are now concentrated in Idlib, in northern Syria.  Idlib is the place to which civilians and members of armed groups were permitted to escape as part of evacuation deals from places like Aleppo and Eastern Ghouta as they fell to government forces. Millions of displaced Syrians and some armed groups are now concentrated there.    But now there is every indication that Syrian forces, backed by Russia, are preparing for battle.    My guest today is trying to warn the world how disasterous such a battle would be for civilians caught in the crossfire. Jan Egeland is a senior advisor to the UN Special Envoy for Syria and heads the UN's humanitarian task force for Syria. As such, it is his job to negotiate access to besieged populations for relief workers and facilitate humanitarian relief in war zones. A battle over Idlib would be a bloodbath, he says, that could jeopardize the lives of 3 million people.     In our conversation, Jan Egeland describes the significance of Idlib to the trajectory of the war , and the geopolitics underpinning a potential decision by the Syrians to lay siege to it. We also discuss what NGOs in Idlib are doing to prepare for a potential attack.     Jan Egeland is a longtime humanitarian professional. He is current the head of the Norwegian Refugee Council and served as the top UN humanitarian relief official from 2003 to 2006. This meant he reported directly to Kofi Annan so we kick off with a brief conversation about the late Secretary General's legacy before discussing Syria at length.