Beijing officials also face intensifying political pressure to stand up for China’s perceived national interests, as many Chinese have become increasingly outspoken and nationalistic in their postings on Chinese Internet sites.
“China feels increasingly under siege as it becomes an international economic power, as others try to contain it,” Mr. Jiang said. “They don’t want to appear to be weak, because domestic pressure is mounting.”
Chinese customs officials stopped exports of rare earth minerals to Japan on Tuesday as tensions mounted over the captain’s detention. While Beijing has denied imposing a ban, Chinese exporters were still waiting Sunday for permission to resume shipments, officials in the rare earths industry said.
The Chinese Commerce Ministry’s decision on poultry import tariffs concluded an investigation that the ministry had begun almost exactly a year ago, less than two days after President Barack Obama imposed steep tariffs on Chinese tires.
The Chinese state-run news media have been critical in recent weeks of pressure from the United States for China to reduce its intervention in currency markets and to allow the value of the Chinese currency, the renminbi, to rise in value against the dollar.
China’s limit on rare earth exports reflects its increasingly assertive combination of diplomatic and economic power. Rare earths are important for the automotive, electronics and clean-energy industries. By abruptly suspending exports of rare earth minerals to Japan, China has put Tokyo and the world on notice that it has a potentially powerful tool for economic sanctions.
China mines 93 percent of the world’s tonnage of rare earths, and more than 99 percent of some of the least common and most valuable rare earths.