The President's definition of a "red line" for North Korea has fueled controversy, with critics questioning its adequacy.
At a press conference to mark his 100th day in office Thursday, President Moon Jae-in said that he would consider North Korea had crossed a red line "if it completes development of an intercontinental ballistic missile (ICBM) and weaponizes it by fitting a nuclear warhead on it."
He also said, "North Korea is nearing the threshold of the red line."
Some people, including Moon's aides, interpreted the rare remarks as a warning to the North on its rapid progress in developing nuclear weapons and missiles. But criticism of his "diplomatic immaturity" was prevalent.
Pundits expressed concerns that the statement narrowed the Moon administration's policy options in dealing with North Korea.
"Moon must be the first leader in the world who went into details of what constitutes a red line," said Nam Sung-wook, a professor at Korea University's department of unification and diplomacy. "Keeping ambiguity suits national interests. Moon may have said so to prevent a U.S. preemptive attack, but still, it exposed our intentions."
Park Won-gon, an international relations professor at Handong Global University, had a similar view. "Development of a nuclear-tipped ICBM targeting the U.S. mainland is North Korea's ultimate goal and there's a high possibility that it will achieve it soon," he said. "What will be our option when it actually happens? Moon has limited his options."
Seoul and Washington have repeatedly urged Pyongyang not to cross a red line, but have not previously stated what level of provocations they considered to be a red line that would activate military options.
Even while ramping up his warning to North Korea, U.S. President Donald Trump has been ambiguous about the red line.
He told the press on Aug. 10, "I'm not like the other administration that would say we're going into Mosul in four months. I don't talk about it." His national security adviser Gen. H. R. McMaster also said in an NBC interview on Sunday, "Trump doesn't draw red lines."
Moon's abrupt revelation of the red line could cause trouble in coordinating North Korea policy with the Trump administration, pundits pointed out.
"Moon's remark was reckless because it appears Seoul has yet to see eye-to-eye with Washington on what level should be the threshold of the red line," Prof. Park said.
He pointed out that South Korea and the U.S. had not established a security consultative body as agreed in the summit between the leaders in June.
Opposition parties upped their offensive against Moon. Main opposition Liberty Korea Party floor leader Chung Woo-taik called it an "unrealistic" red line, saying the North's missile capability had already reached the destructive level for South Korea.
"The completion of developing a nuclear warhead that fits atop an ICBM is a concern of the U.S," Chung said. "For South Korea, the North has many other military options. It has already crossed the red line for us."
Kim Young-woo of the minor opposition Bareun Party, who chairs the National Assembly Defense Committee, also said Moon's remark reflected his complacency in security matters. "He sent a wrong signal to North Korea that he would wait until it completes a nuclear-tipped ICBM," he said.
Meanwhile, North Korea gave a harsh assessment of Moon's 100 days in office through its official newspaper, saying he especially "failed" in terms of inter-Korean relations.
"Moon's conciliatory overture ended in mere rhetoric because he was still under U.S. control," the Rodong Sinmun wrote Friday.