In Syria, aid agencies are warning of a looming humanitarian catastrophe if the United Nations Security Council doesn’t renew its mandate for an aid corridor from Turkey to Syria’s Idlib province. Doctors Without Borders warns more than 4 million people will lose access to desperately needed food, medical and humanitarian aid if the Bab al-Hawa border crossing is closed. It’s the last lifeline into rebel-held parts of northwestern Syria, after Russia and China vetoed Security Council resolutions in 2019 and 2020 that would have reauthorized three other aid corridors.