President Barack Obama was joined Saturday in the Rose Garden by former Presidents George W. Bush and Bill Clinton to announce that his two predecessors will lead a long-term effort to help rebuild the devastated country of Haiti.The show of unity between three U.S. leaders who have toiled in the trenches of political warfare against one another offered a message to Haiti and the world that “America stands united— in its determination to help Haiti in its hour of desperation, Obama said.“When the news media starts seeing its attention drift to other things but there’s still enormous needs on the ground, these two gentlemen— will ensure assistance continues, Obama said. “Our longer term effort will be measured in months and years.—The two former presidents have established an organization with the Web site www.clintonbushhaitifund.org to receive donations to help in the aftermath of Haiti’s recent earthquake.Clinton stood at ease while Bush fidgeted somewhat as the men occupied the same spot where, as commanders in chief, they once delivered messages to the country on matters mundane and great.In their own remarks, both commended Obama for his response to the disaster and said they were happy to help.Obama reminded the country of Bush’s response to the 2004 Indian Ocean tsunami and his work to combat AIDS, but he omitted mention of Bush’s reaction to the 2005 Hurricane Katrina disaster along the Gulf Coast. Bush’s administration was widely criticized for its botched response to Katrina.But Bush mentioned it, including it in a list of catastrophes that “Americans responded to.— Obama said that when he had contacted Bush and Clinton, “they each asked the same simple question, ‘How can I help?’—But Clinton, gently grabbing at Bush’s arm, ribbed the ex-president, saying he had “already figured out how to get him to do some things that he didn’t sign on for.— But Clinton didn’t say what those things were.