UNITED NATIONS — The war in Sudan has created the world’s largest and most devastating humanitarian crisis with over 30 million people needing aid this year, 16 million of them children trying to survive in dire conditions, the head of the U.N. children’s agency said Thursday. With no end in sight to the nearly two-year conflict , Catherine Russell told the U.N. Security Council that children in Sudan are enduring "unimaginable suffering and horrific violence.” An estimated 1.3 million children