Dr. Michael Pillsbury, Senior Fellow and Director, Center for Chinese Strategy, testified before the US Senate (p. 9) on Nixon's visit to China:
But there were glimpses even then that the Chinese saw the United States not as an ally but as an obstacle. Referring to the United States, Zhou offered a hint of how the Chinese really felt about their new prospective friend. “America is the ba,” Zhou told Kissinger’s interpreter, Ambassador Ji Zhaozhu of China’s Foreign Ministry, repeating a term that would be frequently used by Chairman Mao and his successor, Deng Xiaoping.
[...] Kissinger’s translator told Kissinger that Zhou’s statement meant, “America is the leader.” This seemed to be an innocuous remark, and when taken in the context of the Cold War even a compliment. But that is not what the word ba means in Mandarin — at least that is not its full context.
How would that statement have been constructed in Chinese, and to which "ba" was being referred to?