GAZA CITY — It's easy to imagine his frustration, that of a professional whose fate doesn't depend on the quality of his work or his willingness to work hard but on political contingencies. Salaheddin Abu Hassira, 50, is an entrepreneur in Gaza's building sector. It's a pursuit that, in this Palestinian territory, seems condemned to prosper after the wars with Israel destroyed so much.

After Israel's Operation Protective Edge, which lasted 50 days over the summer, villages and entire neighborhoods were ravaged. "I'm impatient for reconstruction to start," Hassira says. But right now it's virtually impossible to begin the work of restoring or rebuilding homes. There isn't any of what is as valuable as gold in Gaza — cement.

Hassira, wearing a khamis (a traditional robe), receives visitors in an apartment located in downtown Gaza City. During the day, he's bored. At night, he earns some money as a guard. It's a step-down socially, but what choice does he have?

"It's been two years since I've had a construction project," he says.

For nine years, during that utterly different period when inhabitants could leave Gaza — which is to say, before Hamas came to power in 2007 — the entrepreneur worked in Israel. He supervised construction sites, commuting back and forth. He collaborated with three Israeli companies, but he was forced to fall back on the Palestinian market, which was soon strangled by the blockade. He's proud of having made a name for himself building residential buildings in various parts of the Gaza Strip.

After this summer he was asked to rebuild a school to the north of Gaza City. "The plans are ready, and town hall has given its approval," he says. "But I need materials like stone, but mainly cement!" Cement can be found at small warehouses on the city's outskirts with sacks lined up to attract passing drivers, but prices have multiplied five or six times since the beginning of the year. And the war only accelerated the trend.

"These past few years, cement came from Egypt via the tunnels," Hassira explains. "Then the Egyptians closed most of the tunnels. Otherwise, there are two major players in the construction sector, Qatar and the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA). Entrepreneurs completing projects divert some of their cement to the black market."

The Palestinian unity government hopes that this market will dry up if they can obtain free circulation of goods at the checkpoints. The problem is it all depends on the goodwill of Israel.

The flow of materials

Benjamin Netanyahu's government keeps issuing warnings about the "dual" usages of certain construction materials. The Israelis suspect they may be diverted for military use, to build tunnels for Hamas attacks, or to make rockets.

Israel is therefore demanding scrupulous watch over imports of materials to and their use in the Gaza Strip. The government is even asking for a file to be created to keep track of individuals and companies wishing to acquire such materials. Many of the Palestinian economic and political players judge such generalized control to be impossible. They are demanding the end of the blockade rather than its institutionalization.

Hamas and the Palestinian National Authority have, however, accepted the presence on the territory of UN observers who can offer guarantees to Israel. But some at UNRWA are skeptical in view of the size of the task at hand. Rafiq Abed, who has worked at UNRWA for 26 years and is currently in charge of piloting major infrastructure projects, explains that the agency "is working on 30 projects at some hundred locations in the Gaza Strip. In total, between 120 and 150 members of our personnel, on all levels, work on controlling the aggregates. We can't even imagine what would be necessary if there were 100 projects."

The president of the entrepreneurs' union in Gaza, Nabil Abu Muaileq, also believes that a complete overview of imported materials is impossible. "You need 10,000 tons of cement per day to rebuild Gaza," he says. "If only 1% escaped control because it was diverted by drivers, workers, deliverymen, that would already be 100 tons gone missing. It would be much better to open the borders, make it possible for people to go work in Israel or Egypt, to live better, to travel. It would work out. Otherwise tomorrow morning or in a year's time things will explode again here."

A more political argument can be added to that, says Omar Shaban, director of Pal-Think, the Gaza-based "think-and-do tank." If the UN took charge of keeping tabs on the materials, "people would no longer perceive the benefits of a return of the Palestinian Authority to Gaza. It would come across as weak."