Syria's cease-fire is crumbling under the weight of current and pending military operations in the country. Focused on the province and city of Aleppo, the operations stand to play a decisive role in determining the direction of the civil war. In the coming weeks, the results of these battles could change the balance between rebels and loyalists, alter the Islamic State's position in the region, and influence the relationship between the United States and Turkey as they pursue conflicting objectives in Aleppo....