US military personnel unloading supplies in Haiti

*Faced with a neighbor in social and political collapse, President Barack Obama and the U.S. moved to take charge in Haiti on Thursday, dispatching thousands of troops along with tons of aid to try to keep order as well as rescue the suffering in a country dysfunctional in the best of times.

Obama responded to the first large-scale humanitarian disaster of his presidency by ordering a relief effort to match the devastation wrought by an earthquake. On Thursday, he pledged $100 million in U.S. assistance, an amount almost certain to grow as the scale of suffering becomes more clear.

Political realities were at play as the U.S. rolled out its response to Tuesday’s earthquake. The U.S. budget and its military are already strained by a financial meltdown and two wars, and President George W. Bush’s disengaged reaction to Hurricane Katrina in 2005 is a reminder of the high price that can come with an ineffective response to a crisis.

Details of evening Situation Room meetings, phone calls with world leaders and canceled events were being released by the White House almost hourly since the 7.0-magnitude quake struck.

“I will not put up with any excuses for us not doing the very best in this time of tragedy,” Obama pledged at the Capitol, making his third public comments on the topic in two days.

The president announced “the first waves” of the American response were in place, with two search-and-rescue teams on the ground, Coast Guard cutters in port, the U.S. Southern Command in control of the airport and airlifts bringing in urgently needed supplies and ferrying out the injured.

But the chief emphasis out of Washington was the huge amount of U.S. help that was still on the way – some half-dozen ships and 5,500 troops making their way across the Caribbean.

“The United States is providing a lot of the glue that is keeping people communicating and working together as we try to assert authority, reinstate the government and begin to do what governments have to do to rebuild,” Secretary of State Hillary Rodham Clinton said on Fox News Channel.

Get MORE of this AP story by Jennifer Loven, HERE.