A Harvard professor argued that Korean women forced into sex slavery in WWII did so voluntarily. Now he's facing a backlash

In this 2017 photo, former "comfort woman" Lee Yong-soo, left, who was forced to serve for the Japanese troops as a sex slave during World War II, shouts slogans during a rally to mark the March First Independence Movement Day. She called Harvard Law Professor J. Mark Ramseyer's claims "absurd."

(CNN)A Harvard professor has sparked international backlash after publishing an academic article arguing that Korean comfort women -- sent against their will to imperial Japan to have sex with soldiers -- were not actually forced into their prostitution but that they actually chose their positions.

J. Mark Ramseyer, a Harvard Law School professor specializing in Japanese legal studies, published his article in the peer-reviewed International Review of Law and Economics in December, scheduled to publish in print this month.
In his article, "Contracting for sex in the Pacific War," Ramseyer argues: "The protracted political dispute between South Korea and Japan over the wartime brothels called 'comfort stations' obscures the contractual dynamics involved." He goes on to illustrate ways that the women of Korea, then under rule by Japan, were actually given voluntary contracts to work for the Japanese army as prostitutes.
      Now, that article and Ramseyer are the subject of international outcry.

        Backlash from both North and South Korea, and surviving 'comfort woman'

          Representatives from China, South Korea and North Korea have all spoken out against Ramseyer's work, arguing that the women were never given a choice.
          In a news conference last month, the Chinese Foreign Ministry spokesperson Hua Chunying said the country opposes "all erroneous acts that whitewash the war of aggression in an attempt to deny and distort history," according to an English translation.
          "The forced recruitment of 'comfort women' is a grave crime against humanity committed by the Japanese militarism against the people of Asian and other victimized countries during the Second World War. It is an internationally recognized historical fact with iron-clad evidence," Hua Chunying said. "We have been asking the Japanese side to earnestly face up to and deeply reflect on history, properly handle the 'comfort women' issue in a responsible manner, and take concrete actions to win the trust of its Asian neighbors and the international community."
          The South Korean Ministry of Gender Equality and Family also spoke on the research, saying that the ministry will continue listening to the opinions of victims.
          In this February 25, 2021, photo, high school students hold up signs protesting research by J. Mark Ramseyer of Harvard. The signs read: "J. Mark Ramseyer, are you a 21st century professor at Harvard? Are you a university professor in the Japanese Empire 100 years ago? We criticize anti-human rights research."
          "With regard to the recent thesis written by a Harvard professor -- which has emerged as a controversial issue -- ... we find them truly lamentable and hope that the case of tarnishing the victims' dignity and honor will no longer be repeated," the ministry wrote in a statement last month.
          And DPRK Today -- a North Korean state media outlet -- called Ramseyer a "pseudo scholar."
          "The person who didn't only support the Japanese reactionaries' shameless and immoral act of covering up their past crimes, but insulted the victims of sex slavery by calling them voluntary prostitutes, is Ramseyer, a Harvard Professor wearing the mask of a so-called 'scholar," the report reads.
          J Mark Ramseyer, the Harvard professor behind the controversy.
          When asked about the research, the US State Department said in a statement to CNN that it has "long encouraged the ROK and Japan to work together on history-related issues in a way that promotes healing and reconciliation."
          "Even while addressing sensitive historical issues, cooperation on our common regional and international priorities must proceed," the statement read. "As the United States has stated many times, the trafficking of women for sexual purposes is an egregious violation of human rights, including by the Japanese military during World War II."
          Following the article's publication and subsequent controversy, activist and surviving comfort woman Lee Yong-soo called Ramseyer's claims "absurd" and encouraged others to "ignore" them, in a webinar panel hosted by the Harvard Asian Pacific American Law Students Association last month.
          Ramseyer did not return CNN's requests for comment.

          Ramseyer's research is now under review

          The International Review of Law and Economics, which published the research, said in a statement that it has issued an "Expression of Concern" on the article, indicating that "concerns have been raised regarding the historical evidence in the article listed above."
          "The journal is in discussion with the author regarding these concerns and has also solicited further post-publication comments from several expert reviewers," the journal said in a statement last week.

          Role of 'comfort women' still tense between Japan and Korea

          "Comfort women" refers to the hundreds of thousands of young girls and women from multiple Asian countries who were forced into sexual slavery by the Japanese military during World War II, according to the United Nations. Many victims have come forward and shared their testimonies, and multiple studies over the last two decades have been conducted into the role the women played.
          Still, "comfort women" has been a tense topic between Japan and Korea.
          Back in 1993, Japan issued the Kono Statement, which a