PORT-AU-PRINCE — The billions of dollars in aid that flowed into Haiti after its shattering earthquake were meant to build a new nation with thriving farms, apparel factories, modern hospitals and paved roads in the countryside.

Ambitious plans call for $500 million to build 50 new grade schools, $200 million to give Port-au-Prince its first wastewater treatment plant and $224 million to create an industrial park for 65,000 garment industry workers — all aimed at laying the groundwork for a new Haiti.

But as the hemisphere’s poorest country marked the second anniversary of the Jan. 12, 2010 earthquake that killed some 300,000 people, only about half of the $4.6 billion in promised aid has been spent. Half a million people are still living in crowded camps. And only four of the 10 largest projects funded by international donors have broken ground.

The optimistic rallying cry promoted shortly after the earthquake to “build back better” has turned out to be much harder to achieve than anyone imagined. Reconstruction efforts have been stymied by the same problems that impoverished Haiti in the first place: chronic political instability, lack of a robust central government and a tattered infrastructure in a nation where, even before the earthquake, half the children did not attend school and more than half the population was unemployed.

Former President Bill Clinton, the U. N. Special Envoy to Haiti, said in an interview Jan. 11 that the reality of Haiti and its complicated history made the hoped-for reconstruction difficult.

“We had massive,

massive problems in Haiti before the earthquake. A lot of this stuff we’re not trying to rebuild; we’re actually trying to do it right for the first time,” Clinton told The Associated Press.

Haiti’s President Michel Martelly also acknowledged that achievements have fallen far short of expectations, describing progress so far as “definitely, not enough,” in an interview with the BBC.

“But, lately, since I have been in power, I will say that we have shown strong signals that things are changing and moving in Haiti,”’ said the president, who took office in May. His squabbles with parliament have contributed to the delays.

The previous administration of President Rene Preval was crippled by the collapse of government

buildings and showed little leadership in the aftermath of the earthquake. The election that brought Martelly to power was marred by irregularities and riots that paralyzed the capital. It took the politically inexperienced Martelly six months to install a prime minister as rival lawmakers rejected his initial two picks.

The administration of Martelly, a former musician, abounds with ambition. His prime minister, Garry Conille, told Parliament Jan. 9 that the government wants to enroll another one million children in school this year, plant trees to stop decades of deforestation and improve health care. Conille calls 2012 “a year of construction.”

But the efforts to create a new country so far have been met with frustration.  Lawmakers have grumbled that they witness little happening. Camp dwellers have demonstrated against the lack of housing and the evictions that have pushed them elsewhere. Others are exasperated over news of billions of dollars in aid that yields few visible results — large or small.

The 10 biggest internationally funded projects approved by the Interim Haiti Recovery Commission or IHRC are ambitious and complicated. They involve multiple partners, require bids for contracts and address a range of needs from job creation and health to energy, sanitation and education. It will take years for them to reach completion.

“Reconstruction is not the same thing as humanitarian work; humanitarian work has to be done quickly,” said Diego Osorio, of the Haiti Reconstruction Fund which helped finance IHRC-approved projects. “Reconstruction projects require planning and there are not going to be visible accomplishments on a day-to-day basis.”

Yet even the planning has suffered. The recovery commission co-chaired by Clinton was set up to assure foreign donors that their money wouldn’t go wasted. The panel helped coordinate multi-million-dollar projects in a relatively transparent fashion and avoid duplication.

But in October the commission’s 18-month mandate ended, halting work on future projects, because opposition lawmakers took no action on a request by Martelly to renew the mandate for another 12 months.

So far, the biggest completed project is a $30

million state-of-the-art university in northern Haiti built by the Dominicans. On the second anniversary of the quake, Martelly and President Leonel Fernandez of neighboring Dominican Republic inaugurated the campus which has 72 classrooms, science and computer labs and a library for as many as 10,000 students.

Another project under way is the U.S.’s most ambitious. Budgeted at $224 million, the Caracol industrial park is taking shape as bulldozers clear a field for an industrial park run by South Korean garment manufacturer Sae-A Trading Co. Ltd. The project is expected to bring 65,000 jobs to a remote area outside the second largest city, Cap-Haitien, with the first batch of T-shirts scheduled for production by September.

But the majority of the projects have been delayed by an array of problems ranging from an inability to secure funding to land disputes.