Further military cooperation with the United States is vital to maintain a bilateral security alliance the nation cannot do without, former Ambassador Hirohisa Okazaki told a Diet committee Wednesday.

Speaking at the Lower House special committee on the revised Japan-U.S. defense guidelines, Okazaki, one of four experts who were invited to present their views during the morning session, said he fears Japan may rearm on its own as it did before World War II should it fail to uphold the alliance with the U.S.

"Asia's stability is proportional to the strength of the Japan-U.S. alliance," said Okazaki, a former ambassador to Thailand. "Our top priority now is to secure our peace and prosperity. Some people broach the concept of Japan's independence (in discussing the guidelines), but that only confuses the discussion," he said.