At the same time, we have few pleasant choices to uplift Port-au-Prince from violent anarchy. With the high stakes of starvation and death, the gangs have plenty of motivation to "fight to the death". We cannot hold the gangs back from armed competition through negotiations, because of the high incentives from going violent.
At the same time, there were few police in Haiti to begin with, plus the 9,000 UN peacekeepers. Without a massive infusion of police and military into Haiti, we cannot guarantee a completely fair distribution of food and water. The abject poverty of Haiti encourages the gangs to hoard as much supplies as possible, for the day when yankees leave. Wherever out of sight of the soldiers, they will be fighting over that one bag of flour.
If we will not send in the military (American or Brazilian), the fastest way to restore order in Haiti will be to ally ourselves with the strongest gang in every district. They are the biggest boots on the ground, the ones best able to secure their own families. At the same time, it will mean the near-death of their local rivals.
On balance, though, the near tyranny of the lord of the town is better than a fought-over street corner, for the civilians. At least they don't have to worry about the stray bullets. Not picking a side in the gang warfare only prolongs the violence on civilian supporters.
Long-term, Haitian agriculture cannot support the population density on the island. Therefore, Haiti has to industrialize and develop its tourism industry. Economic development, however, cannot take place in anarchy. There has to be order before business can flower.