Grand Forks is not a dying city in desperate need of work. Unlike Maine, where Chinese investors resurrected an old mill a few years ago, or Ohio, where a Chinese glassmaker set up shop in an abandoned General Motors plant, there’s no job crisis in Grand Forks. The city is growing, the metro unemployment rate is below the national average, and employers are hiring. In addition to jobs in agriculture and the military, residents work in manufacturing or at the University of North Dakota, known for its aviation program and high-powered hockey team. But Mr. Bochenski, the mayor, has emphasized Fufeng’s economic benefits for his city, where 18 percent of residents live in poverty, well above the national rate. Farmers welcomed the project as a new place to sell their corn, which grows in abundance in the fertile soil along the Red River. And Governor Burgum, a former businessman, has repeatedly stood by the plan. “With Fufeng in Grand Forks, it will be North Dakota — not China — that will reap the benefits of the jobs, facilities, economic activity and tax revenue associated with corn processing,” a statement said of the governor. It is quite common for a Chinese company to do business in the United States and for an American company to do business in China. But as diplomatic relations have soured, American officials, especially Republicans, have questioned whether the United States has grown too close to China economically and whether seemingly innocuous Chinese investments could be used for nefarious purposes.