American marines are providing security for aid distribution, the navy says
By Steve Kingstone
BBC News, Haiti
In a boggy field west of Port-au-Prince, a Haitian man wants water.
"Sir, you'll have to speak to the UN guys," replies the American marine overseeing helicopter deliveries, gesturing towards Sri Lankan peacekeepers beside a pick-up truck.
"No, I'm thirsty and you've got water," persists the man, eyeing a batch of bottles coming off the chopper.
"Get me your boss."
The Haitian has breached a security cordon of rusty barbed wire and rifle-wielding marines.
A commanding officer is called, followed by a Haitian-American soldier to mediate.
After much finger-pointing the interloper departs triumphantly, clutching four bottles of spring water.
"Most of the rifles are not loaded," confides a junior officer, glancing at the restive crowd of locals being kept back from the airfield.
"And if we had a situation here we would respond with non-lethal rounds." He hastily adds that there has been no trouble thus far.
We are in Cassagne, an impoverished rural hamlet which felt the full force of the earthquake. Flying in on a marine helicopter, I witnessed Mother Nature's grim lottery: some houses untouched by the tremor, alongside homes completely flattened.
A community in need at the best of times, and now completely shattered, is adapting to a humanitarian invasion.
On Cassagne's rudimentary streets, UN vehicles jostle for space with tap-taps, Haiti's tightly-packed multi-coloured buses. Giggling children teach snippets of Creole to fresh-faced marines, while an emaciated cow strays perilously close to a cargo helicopter.
"We're pleased the Americans are here," explains one Haitian onlooker, "but we can't understand why aid isn't being given to us."
There are shouts of agreement from a small crowd, which has gathered around an aid truck. The marines wave them back.
Water stacked high at Port-au-Prince is strictly allocated
"You have to focus your efforts on the places that need it most," explains Sgt Clark Carpenter, a spokesman for the US Marine Corps.
"There are areas that haven't been reached."
He stresses that basic aid supplies were handed out in Cassagne when the marines first arrived.
On the face of it, there is collective responsibility for the relief effort - with the Americans controlling the skies, and UN personnel directing the delivery of aid on the ground. And all give a courteous mention to their partners in the Haitian government.
But in practice, the inescapable impression is that the US military is calling all the shots that count. Go to the landing strip at Port-au-Prince airport and you will struggle to find a Haitian face. American troops are everywhere.
"If we have been perceived as trying to dominate, I don't think it was intent on our part - it might simply be because we have a lot of stuff," ponders Rear Adm Ted Branch, who leads the maritime component of the US effort.
His own "stuff" is the USS Carl Vinson, a monster aircraft carrier 332m long and weighing 103,000 tonnes.
The ship cost $3.8 billion (£2.3bn), roughly half the annual GDP of the nation it is aiding.
To date, the US navy has deployed 20 ships off the Haitian coast, as part of an overall deployment that has the feel of a third front, after Iraq and Afghanistan.
Sharing amid security
At the start of the relief effort, Rear Adm Branch acknowledged a lack of co-ordination between the US contingent and other agencies, together with security issues in landing zones.
One week on he is more upbeat.
"We shifted to a system where we only deliver relief supplies in a controlled environment," he explains.
"If we have security and a system on the ground, it means everyone gets their share of the rations - not just the strongest."
Time and again, US personnel of all stripes insist they are visitors not occupiers, clearly mindful of America's chequered past here.
Elderly Haitians may even recall the 19-year US occupation of their country (1915-34), to protect American investments amid political instability.
The US Navy could be in Haiti for months
"We've reinforced to the troops the sensitivity of our image," explains marine Col Jack McElroy, "that we're here to help these people. And trust me, the marines and the sailors are on board."
How long will they be here? Quite conceivably, beyond August - when US combat troops are scheduled to withdraw from Iraq.
"There will certainly be a naval presence here for months," acknowledges Rear Adm Branch.
In a country with minimal strategic or economic significance for the US, this massive deployment reflects a genuine desire to help a neighbour in need.
And given the sheer scale of Haiti's devastation, it may be that US military muscle is the only realistic way to fix things.
But expectations are huge.
An emotional US President Barack Obama promised Haitians: "You will not be forsaken."
As rescue and relief efforts give way to long-term reconstruction, his good intentions will be put to the test.