The world faces potential dangers as Japan and the US bolster their defense ties and ramp up their capability to intervene in global hot spots, according to military observers at a security conference in Beijing.

They also said that Japan, urged on by the United States, is worsening regional tensions by strengthening its military presence in the South China Sea.

Speaking at the Second International Conference on China-Japan South Korea Security Cooperation, which opened on Monday in Beijing, Jiang Xinfeng, an expert on Japanese studies at the People's Liberation Army Academy of Military Science, cited an increasing possibility that Japan will become more involved with the US in regional and global disputes.

The alliance can have global reach, Jiang said, since the two countries revised their framework - Guidelines for US-Japan Defense Cooperation - in April last year.

The guidelines give Japan a green light to exercise collective self-defense, allowing it to defend not only its own territory but also that of the US or other countries.

"The revised guidelines changed on six points regarding the alliance between Japan and the US, including taking cooperation to a global level," Jiang said.

Under the new guidelines, Japan and the US will be able to undertake joint operations across regions, bestowing a higher status on Japan in the alliance, she said.

They will be able to cooperate in all areas, as ocean, aerospace and communication networks are included in their common concerns, she said.

Gong Dugang, a researcher at the Naval Military Studies Research Institute of the PLA, said Japan is restraining China's island construction and regular military deployment by hyping up the disputes with other countries in the region.

"Japan's engagement creates great uncertainty in the South China Sea issue," Gong said.

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