Troops are needed to maintain order in a demoralized and disorganized country. The planned 16,000 may have to be augmented.

Aid workers, including US Military medical personnel aboard hospital and support ships, seem to be there or on the way in sufficient numbers.
Logistics of supply is a major problem, needing careful, central management.

One reason many people support charities other than the Red Cross is its very high administrative and personnel costs, also a reason for its somewhat lower rating on the Charity Navigator, linked by Joe Offer.