On August 15, more than half a century ago, the surrender of Japan was announced to Japanese public and the world by Emperor Hirohito. No matter how bitter and disgraceful an event this might have been in Japanese history, this marked the end of the sufferings brought about by World War II.
Despite the fact that 55 years have passed since the end of the war, one ugly legacy created by Japan remained unresolved: the issue of “comfort women” (“ianfu” in Japanese). This term refers to the Japanese military’s forceful recruitment and sexual enslavement of Asian women, especially those from the countries colonized and occupied by Japan during World War II. 
Military prostitution was a prevalent practice during and prior to World War II. However, Japan’s comfort women serve as an extreme example because this system involved serious inhumane tactics such as coercion and deceitful luring. 
In June 1991, the Japanese government denied its involvement in operating a military brothel system. This provoked a South Korean woman, Kim Hak-soon to stand up to the government, and attest her experiences as a former comfort woman. 
Her testimony led Japanese historian, Yoshimi Yoshiaki, to examine the archives of the Self-Defense Agency (Boejcho), and gather evidence to demonstrate the role of the Japanese Imperial Army in the organization of the system. Once the historian published the evidence, the Japanese government could not evade the issue. Prime Minister Miyazawa Kiichi offered an official apology to South Korea. 
This apology angered Japanese nationalists, and ignited domestic disputes, particularly, between nationalists and progressive/feminist historians. The nationalists aggressively responded by objecting to the government’s admission of its involvement, and even attacking the political figures and historians who advocated the apology. 
In 1994, the coalition cabinet under the leadership of then Prime Minister, Tomiichi Murayama, proposed the establishment of Josei no tame no Ajia Heiwa Yuko Kikin (Asia Peace and Friendship Fund for Women). This fund focused on compensation on the basis of moral responsibility; however, it allowed the Japanese government to evade legal responsibility. Thus, compensation claimants objected to the fund. 
The original source of the problem that has kept this issue alive is the failure of the International Military Tribunal for the Far East (“the Tokyo Tribunal”) to address the “comfort women” charges.  However, there can be no doubt whatsoever that Japan violated international law. First of all, Japan violated international treaty law.
Japan is a signatory to the International Agreement for the Suppression of the White Slave Traffic of 1904, which bans the trafficking of under-aged and adult women for prostitution through deceitful and forceful methods. The International Convention for the Suppression of the Traffic of Women and Children of 1921 (the 1921 Convention), to which Japan is also a signatory, not only bans trafficking but also makes it explicit that the duty of all signatories to prevent it. The comfort women system constitutes a violation of the treaty. 
Secondly, though Japan did not ratify it, the 1926 Slavery Convention nevertheless binds Japan as customary international law along with the above agreements. This convention prohibits the practices of slavery and slave trading. 
In addition to the 1921 Convention and the 1926 Slavery Convention, the 1907 Convention Respecting the Laws and Customs of War on Land imposes on a state both the duty to prosecute such unlawful acts and the duty not to commit them. Japan obviously did not abide by these rules of international law. 
Thirdly, Japan violated jus cogens, which are peremptory norms of international law, allowing no derogation. For instance, enslavement has been considered a jus cogens violation and sexual slavery and violence are recognized by international law as jus cogens war crimes. 
Japan has defended itself by maintaining that the 1951 San Francisco Peace Treaty and the 1965 Agreement on the Settlement of Problems Concerning Property and Claims and on Economic Cooperation between Japan and South Korea have already settled all war claims against Japan. However, the 1951 Treaty only recognizes reparation claims between states, not claims made by individuals. The 1965 Settlement Agreement confines claims to economic and property issues. 
As no progress had been made in the international arena, on September 18, 2000, former comfort women victims attempted to make their voices heard by initiating a class action suit in the U.S. District Court for the District of Columbia (Hwang v. Japan). As foreign nationals, they were entitled to file a suit in a U.S. federal court under the Alien Torts Claim Act (ATCA), which prescribes that “The district courts shall have original jurisdiction of any civil action by an alien for a tort only, committed in violation of the law of nations or a treaty of the United States.” 
Unfortunately, their ATCA claims were counteracted by the Foreign Sovereign Immunities Act (FSIA) because it ensures that foreign states are outside the jurisdiction of U.S. courts by offering presumptive immunity unless the FSIA’s exceptions are met. The claimants challenged Japans’ immunity on the basis of two of the FSIA’s exceptions: a state’s explicit or implicit waiver of its immunity and the commerciality of the relevant action. 
They argued that Japan had explicitly waived its right to immunity by signing the Potsdam Declaration, which indicates that Japan is subject to criminal trials for violations of the law of war. They also maintained that the comfort women system constituted commercial activity because it earned revenue under the supervision of Japanese authorities. The court ruled that Japan was entitled to sovereign immunity under the FSIA and that the plaintiffs’ claims presented a non-justiciable political question. 
The court’s ruling was the outcome of the intervention of the U.S. State Department, issuing a Statement of Interest asking that the court dismiss the case on the basis of political question doctrine.  It seems that the intervention stemmed from concern regarding the U.S.-Japan alliance.
On July 30, 2007, the U.S. House Representative passed the non-binding House Resolution 121 (introduced by Japanese-American Congressman Mike Honda), the so-called “Comfort Women” Resolution, calling on the government of Japan to unequivocally admit to and apologize for its responsibility in relation to the “comfort women” system. The Japanese government made a counterclaim by posting an ad in the Washington Post claiming the women were paid for prostitution. 
The congressional move arose from the awareness that Japan’s historical disputes, including its denial of responsibility in the matter of the comfort women, did not help tune the U.S.-Japan alliance to the fluid stability in East Asia- China was rising and North Korea was in possession of nuclear weapons, and it has troubled other U.S. allies in Asia. 
On the other hand, the Bush administration had no choice but to side with Congress this time. The administration found it too difficult to turn a blind eye to Japan’s neglect regarding international historical issues, since the U.S. had spoken out and pursued forming an alliance on the basis of shared democratic values.