Invade Haiti?

I was wondering, with Haiti in its current state, has the time come for the United States to send to its shores a contingent of troops large enough to establish something akin to martial law, at least for a time? Haiti was effectively a failed state before the earthquake and is even less of a functioning one now. The relief effort is frustrated not only by the destruction of the country's already minimal and marginal infrastructure, but also by the near absence of any local authority legitimate enough to direct the effort and at the same time ensure the safety and security of the relief workers. As something will inevitably fill that void, and likely something bad, is it in our interest and the interests of the Haitian people that that something be the United States?

Haiti is not only in our hemisphere, it is practically a next-door neighbor. In the past, the consequences of its many problems have too often made their way to our doorstep. Is there any doubt that after the current disaster they will soon be in our house altogether? We are the only country that can even contemplate such an action, the only one with the necessary power and resources. While some in the region would likely raise their voices against such an action, labeling it quasi-imperialistic, for example, we can be sure the people of Haiti themselves would welcome it. Moreover, as the leader of the 'invasion' would be named Obama and not Bush, we can also be sure the media would find a way to stifle their opposition, if not become wholly enthusiastic cheerleaders.

The problem, as I see it, is when and how would we terminate such an action? If our chief reason for going is humanitarian in nature, by what standard would we decide to leave? When the average standard of living of the average Haitian rises to the level of...what? The average Dominican? The average Puerto Rican? The average Miamian? I was just wondering.