Japan's self-defense forces have become more involved in U.S. operations since a law was passed in 2015, according to a press report. File Photo by MC1 Michael Russell/U.S. Navy | License Photo

SEOUL, March 29 (UPI) -- Japan's military has become increasingly involved in the protection of U.S. carriers and aircraft since the passage of a law in 2015 that allows Tokyo's self-defense forces to operate overseas.

An analysis of Japanese military documents shows self-defense force activities involving U.S. warships and aircraft rose steadily beginning in 2017, Tokyo Shimbun reported Friday.


The 2015 legislation went into effect in 2016. That year, Japan did not deploy any of its assets to escort or defend traveling U.S. carriers or planes. In 2017, the Japanese military recorded two such events, and by 2018 the number of missions to "protect" rose to 16, according to the report.

Documents analyzed by the Japanese newspaper indicate in 2017 the SDF conducted activities that included protecting one U.S. aircraft and one U.S. ship during joint training.

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In 2018, Japan carried out similar "protection" activities 13 times, and during joint drills. The SDF also provided protection for U.S. naval destroyers during intelligence-gathering missions.

Japanese media describes the changes as a sign the two militaries are "merging" at an accelerated pace.

On Thursday, Japanese Chief Cabinet Secretary Yoshihide Suga said the "U.S.-Japan alliance is stronger than ever," and that it has contributed to enhanced deterrence, and to the peace and stability of the region.

In Japan, critics are wary of Tokyo's involvement in U.S. operations.

Kyoji Yanagisawa, a former assistant to the deputy chief cabinet secretary, said in an editorial in the same paper Japan cannot guarantee its security if it has to continue protection for U.S. forces in places like the South China Sea, where the United States conducts freedom of navigation operations.

It is unclear whether Japan ever extended its operations to waters claimed by China.

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Japanese Prime Minister Shinzo Abe could be seeking further amendments to Japanese law, but a former prime minister said Friday Abe would be prevented from taking such measures, South Korean news agency Yonhap reported.

Yukio Hatoyama, a former Japanese prime minister, said Abe would not be able to amend the constitution because Japanese citizens will oppose the changes.

Hatoyama was speaking at a forum in Seoul on South Korea-Japan relations, according to the report.