Whether Japan’s Self-Defense Forces may be allowed on the Korean Peninsula in the event of a military clash here has become a hot point of contention between Seoul and Tokyo since Japan passed new security laws that allow its Self-Defense Forces to engage in collective self-defense and fight in conflicts overseas.

Koreans who suffered brutal Japanese colonial rule from 1910-1945 find the possibility of the Japanese military setting foot on Korean soil again simply unacceptable. Hence, when Prime Minister Hwang Kyo-ahn, during a questioning at the National Assembly on Oct. 14, said that the government could allow Japan’s Self-Defense Forces into South Korea during a military crisis to protect Japanese citizens here, the remark was met with public outcry.

In stating that Japan’s Self-Defense Forces must receive consent from Korea before entering the Korean Peninsula, the Korean government refers to Article 3 of the Constitution of the Republic of Korea: The territory of the Republic of Korea shall consist of the Korean Peninsula and its adjacent islands.

That position was directly challenged, however, by Japanese Defense Minister Gen Nakatani during a meeting with Defense Minister Han Min-koo in Seoul on Oct. 20. During the meeting of the defense ministers of the two countries, the first since January 2011, Han reaffirmed that Japan’s Self-Defense Forces would need consent from the Korean government to enter the Korean Peninsula. Nakatani, however, challenged that position, claiming that “there are some opinions that the scope of South Korea’s effective control is below the truce line.”

When Nakatani’s statement became public first through Japanese media reports, it was met with public anger at the Ministry of National Defense for what was perceived as an attempt to conceal a crucial part of the bilateral meeting and at Japan for challenging Korea’s sovereignty.

Soon thereafter, Ambassador Sung Kim, U.S. deputy assistant secretary of state in charge of relations with South Korea and Japan, offered clarification. Referring to the revised guideline between U.S. and Japan that “very clearly states the importance of respecting the sovereignty of a third country,” Sung said, “It’s obvious that Japan would not operate on the peninsula without South Korea’s consent.”

Seoul quickly set about containing the damage. Meeting with opposition party leaders last Thursday, President Park Geun-hye said that whether Japan’s Self-Defense Forces entered the Korean Peninsula was a decision to be made by the president. The next day, National Security Office Chief Kim Kwan-jin told the National Assembly that the Constitution states that the Republic of Korea has sovereignty over North Korea and Japan’s Self-Defense Forces cannot enter North Korea without South Korea’s approval.

Nakatani’s statement on Korea’s sovereignty has opened Pandora’s box. Successive Korean administrations have used Article 3 of the Constitution in declaring sovereignty over North Korea. However, Nakatani very openly and directly challenged that position and it is a challenge that is not entirely groundless. For example, South Korea and North Korea simultaneously became member states of the United Nation as two separate sovereign states.

Cool heads — not heated emotions — should prevail in formulating a well-reasoned response, one in step with international laws, to Nakatani’s challenge and similar challenges by others that may follow as separate sovereign states.