(Reuters) – Haiti is facing a humanitarian crisis, with shortages of food, fuel and water causing catastrophic hunger, and the government pleading for military assistance from abroad. WHAT IS CAUSING THE CRISIS? The trigger for the current crisis is the blockade of a key fuel terminal by armed gangs that began in September. That has led to shortages of gasoline and diesel and halted most transport, in turn creating shortages of basic goods, including clean water. WHO ARE THE GANGS LEADING THE BLOCKADE? The blockade is being led by a coalition of gangs called G9, which controls areas in and aro…