Protesters stage a protest against Japan's decision to acquire the capability to strike enemy bases in front of the Japanese Embassy in Seoul, Tuesday. Yonhap

By Kang Seung-woo

The South Korean government is advised to explore ways with the United States to stop Japan from deciding on its own to carry out an attack against North Korea, an act that could infringe on the South's sovereignty.

The Japanese government unveiled a new national security strategy last week, and the development of counterstrike capabilities ― one of three updates ― has emerged as a hot-button issue in South Korea as it allows Tokyo to strike at missile launch sites within North Korea in the event of an emergency.

The South Korean government claims that the exercise of such an action definitely requires Seoul's consent, because North Korea is part of the Korean Peninsula, which the South Korean Constitution defines as part of South Korea's territory, while also having a significant impact on security on the peninsula and the South's national interests.

However, a Japanese government official told reporters, Friday, its exercise of the counterstrike capability does not require approval from other nations as it is a self-defense measure.

"The biggest concern is about the Japanese military's involvement on the Korean Peninsula in peace time, which might violate sovereignty," said Go Myong-hyun, a senior fellow of the Asan Institute for Policy Studies.

"We need to strongly express our concerns over the issue to the U.S. as it is linked to our national sovereignty," he added.

Upon the release of the new national security documents, the U.S. government fully welcomed the revisions, as evidenced by U.S. President Joe Biden's tweets that said, "The United States stands with Japan at this critical moment" and "Our alliance is the cornerstone of a free and open Indo-Pacific and we welcome Japan's contributions to peace and prosperity."

In addition, Japanese Prime Minister Fumio Kishida plans to visit Washington, D.C. next month to discuss its military buildup with Biden, according to Japanese media outlets.

The updated national security documents stipulate that Japan needs counterstrike capabilities which, in the case of missile attacks by an opponent, enable the country to mount effective counterstrikes against the opponent to prevent further attacks while defending against incoming missiles by means of the missile defense network.

However, some claim that the new strategy failed to go into detail about which situations will allow Japan to mount a counterstrike against the opponent.

Park Won-gon, a professor at Ewha Womans University, said the South Korean government needs to sit down with the U.S. and discuss the counterstrike issue.

"The South Korea-U.S. alliance and the U.S.-Japan alliance are mutually connected and they do not work separately," he said.

"Putting all available scenarios on the table, the South Korean government should talk with the U.S. side on the issue and the role of Japan," Park added.

Go also said, "The U.S. has been seeking to enhance trilateral cooperation with South Korea and Japan and in that sense, we need to make efforts to get Japan to exercise the counterstrike capability under the frame of the three-way cooperation."

Meanwhile, North Korea criticized Japan's decision, Tuesday, to develop its counterstrike capability, warning of "actual action" in response.

Its foreign ministry said in a statement, carried by the state-run Korean Central News Agency, that Japan was causing a grave security threat to the region by adopting the new policy of acquiring counterstrike capabilities against other nations.

It also said the move has changed security conditions in East Asia fundamentally, adding that Japan will learn that its move was a wrong and dangerous choice.

The ministry added that Pyongyang will continue to demonstrate through practical actions how much it is concerned and displeased with Japan's move.