Prof. Andrew Nathan quoted in the NY Times:

50 Years Later, Some Question Value of U.S.-China ‘Panda Diplomacy’
In 1972, China sent two pandas to the United States as a gesture of good will. In recent years, experts say the animals have taken on a new role: softening China’s authoritarian image. . .
. . . “It’s soft power,” said Andrew J. Nathan, a political science professor at Columbia who specializes in Chinese politics and foreign policy. “Pandas are very cute and lovable,” he said, “so it fits into that kind of friendship diplomacy image" . . .