A U.N. mechanism facilitating the transit of cross-border aid into northwestern Syria has expired, potentially leaving millions without deliveries of food, medicine, clean water and other humanitarian aid.The mechanism, which expired Sunday, was first authorized by the U.N. Security Council in 2014. However, it did not get the needed extension as the council failed to adopt a resolution authorizing it amid divisions between the West and Russia over the latter's invasion of Ukraine.Aid from Turkey reaches 2.4 million Syrians living in the rebel-controlled region through the mechanism each mo…READ FULL ARTICLE