Major General Zhu Chenghu received an ''administrative demerit" recently from the National Defense University, which bars him from promotion for one year, said the sources, who requested anonymity.
''He misspoke. But the punishment could not be too harsh or we would be seen as too weak towards the United States," one source said.
An administrative demerit is the second lightest punishment on a scale of one to five, but still potentially damaging to his career. The lightest is an administrative warning, while the heaviest is expulsion.
''His chances for promotion in the future are extremely slim," another source said.
The Defense Ministry declined to comment.
In July, Zhu told a group of visiting Hong Kong-based reporters China would have no choice but to resort to nuclear weapons in the event of a US attack over democratic Taiwan, which Beijing has claimed as its own since their split at the end of the Chinese civil war in 1949.
Beijing knows that action is needed to prove its claims to peaceful development. And it is showing the world its determination. It is hardly a co-incidence that the 3 pieces of news reach the international press at the same time, especially that of Major General Zhu, who is the grandson (some said nephew) of Red Army Commander Zhu De.