The deal was questionable from its inception. With no open bidding process, Union Development was handed a 99-year lease on a concession triple the size of what Cambodia’s land law allows. The company was exempted from any lease payments for a decade.

On Dec. 9, Gen. Kun Kim, a former military chief of staff, and his family became targets of United States Treasury sanctions for profiting from relationships with a “China state-owned entity” and for having used “soldiers to intimidate, demolish and clear out land.” While the Chinese firm was not named, rights groups and local residents said it was Union Development.

Presiding over the signing of the Dara Sakor deal in 2008 was Zhang Gaoli, once among China’s top leaders. The company’s promotional materials call the development “the largest seashore investment project not only in Southeast Asia but in the world.”

Even with generous lease terms, the one part of Dara Sakor that has been built, a resort complex, is languishing. On a recent day, the golf course was empty and the casino deserted. The marina restaurant attracted one Chinese family, which had brought seafood in a plastic bag to avoid paying resort prices.

Instead of retreating from a faltering venture, Union Development has doubled down. The new construction at Dara Sakor includes a 10,500-foot runway and a deep-sea port able to handle 10,000-ton vessels.