BEIJING (Reuters) - Eighteen months before Japan's radiation crisis, US diplomats had lambasted the safety chief of the world's atomic watchdog for incompetence, especially when it came to the nuclear power industry in his homeland, Japan. Cables sent from the US embassy in Vienna to Washington, which were obtained by WikiLeaks and reviewed by Reuters, singled out Tomihiro Taniguchi, until last year head of safety and security at the International Atomic Energy Agency (IAEA). "For the past 10 years, the Department has suffered tremendously because of (deputy director general) Taniguchi's weak management and leadership skills," one said on Dec 1, 2009. "Taniguchi has been a weak manager and advocate, particularly with respect to confronting Japan's own safety practices, and he is a particular disappointment to the United States for his unloved-step-child treatment of the Office of Nuclear Security," said another, which was sent on July 7, 2009. The IAEA does not comment on the contents of leaked cables. The evidence of concern about the Japanese national surfaced as his country scrambled to avert a lethal spread of radiation from earthquake-damaged nuclear reactors north of Tokyo. Diplomats accredited to the IAEA said the agency could play only a very limited role in safety and security because it could make recommendations and provide incentives for states to make improvements, but not enforce them.