Introduction

　Japan entered the Heisei era on January 8, 1989, when Emperor Showa passed away, and Crown Prince Akihito became his successor. On May 1, 2019, the Reiwa era began with Emperor Akihito's abdication and Crown Prince Naruhito's accession to the throne.
The start of a new Japanese era--be it Showa or Heisei--does not necessarily signify a change in zeitgeist. However, 1989 happened to be an important year in world history--the fall of the Berlin Wall in November and the US-Soviet summit in Malta in December brought about the end of the Cold War. Besides, in June of that year, the Tiananmen Square incident occurred in China. This was a major turning point in China's development to this date. In other words, the start of the Heisei coincided with significant events.
　The Cold War was not only a confrontation between the United States and the Soviet Union but also an international order. Both the West and the East rallied behind their respective major powers and confronted each other. Although there were exceptions, such as the confrontation between China and the Soviet Union, the Cold War constituted the basic order of the world.
　Therefore, the end of the Cold War meant the end of one system, which accompanied the fluidization of the order. The examples include the reunification of Germany (October 1990) and the collapse of the Soviet Union (December 1991). Besides, regional conflicts, such as the Gulf Crisis (August 1990) and the civil war in Yugoslavia (1991 - 1999 or 2001), became frequent.
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1. From the End of the Cold War to the Redefinition of the Japan-US Security Treaty: 1989-1995

The Gulf War
　The first major shock was the Iraq's annexation of Kuwait in August 1990. This was the biggest violation of the UN Charter since the establishment of the United Nations (UN), following which the UN Security Council (UNSC) passed a series of resolutions to form a multinational force. Although it was not one like the UN forces formed during the Korean War, it had some resemblance.
　Had this happened during the Cold War, it is highly likely that either the United States or the Soviet Union would have stopped Iraq from invading, and the formation of multinational forces would have been prevented by one or another veto of UNSC's permanent members. The Gulf crisis would not have happened without the end of the cold war.
　Japan's response to it was inadequate. Prime Minister Toshiki Kaifu said he would not send the Self-Defense Forces (SDF) into dangerous areas. Although Japan initially contributed $3 billion and later $13 billion, it did not make other contributions. Some argued that the SDF should be allowed to participate in transportation, logistic support, medical care, and minesweeping, even if it was unable to engage in combat operations. Nonetheless, such people remained the minority.
　The war began in January 1991 and ended in a short time. Kuwait did not include Japan in its official declaration of appreciation. Japan became painfully aware that it is its duty as a member of international society to share risks in addition to financing. Even today, the Japanese media sometimes calls this the trauma of the Ministry of Foreign Affairs. To be precise, it should be called the trauma of Japan. The Japanese media that refuses to call it so are, even now, probably still opposed to Japan's participation in multinational forces.
　In fact, there had been concerns among some people that Article 9 of the Constitution does not allow Japan to participate in UN forces since the adoption of the Constitution (1946). In those times, Japan was under occupation and, of course, not a member of the UN. They argued that once Japan would become a member, it might be obligated to participate in UN forces. Nonetheless, successive governments did not consider this possibility seriously.
　Shocked by the Gulf War, the Liberal Democratic Party (LDP), led by the Secretary General Ichiro Ozawa, began studying the possibility of military cooperation with the UN. However, neither the opposition led by the Social Democratic Party of Japan (SDPJ) nor the majority of LDP was keen on it. Germany, which was also a defeated nation and cautious about sending troops outside its territory, revised its constitution to allow such actions in the wake of the Gulf War. Compared with that, the movement in Japan was slow. Although moves to revise the Constitution grew――such as Yomiuri Shimbun established the Research Commission on the Constitution (1992), they did not develop into a major movement.

Initiation of PKOs
　However, growing calls for Japan to at least participate in the UN peacekeeping operations (PKOs) led to the enactment of the International Peace Cooperation Law in 1992. In the autumn of the same year, Japan participated in the UN's PKO in Cambodia (UNTAC), which was the first experience for the country.
Nevertheless, strict restrictions on the possession and use of weapons were placed on the Japanese personnel by the law. Those flaws were repeatedly pointed out in subsequent PKOs, requiring its revision. During the UNTAC, the Japanese contingent suffered total of two deaths, one from the police and another from a NGO, after which the former developed an inward-looking attitude. Nonetheless, it may be said as a big step in terms of Japan's international cooperation.

Security Issues and Political Reforms
　Even among the supporters of opposition parties, there was a growing belief that the fantasy pacifism would not work. The formation of the Japan New Party in 1992 in conjunction with the movement of Ozawa within the LDP led to the formation of the Hosokawa Cabinet in July 1993, the first non-LDP coalition government in 38 years. Under this administration, the conventional election system, centered on the multiple-seat constituency system, was amended in January 1994. It was expected that, with emergence of realistic opposition parties, there would be more competition between the ruling and opposition parties. However, the Hosokawa Cabinet collapsed in March 1994, and the Tsutomu Hata Cabinet, which succeeded it, also collapsed in June, resulting in an unexpected coalition cabinet between the LDP and the SDPJ with Tomiichi Murayama as prime minister.

Murayama Cabinet and the History Issue
　The Murayama Cabinet succeeded the LDP's diplomatic and security policies, including its endorsement of the Japan-US Security Treaty and the Self Defence Forces. On the other hand, the cabinet released the Murayama Statement on the 50th anniversary of the end of World War II and the statement of Chief Cabinet Secretary Yohei Kono on the issue of so-called Korean comfort women, which showed the Japan's attitude of facing its responsibilities. On the comfort women issue, the Asian Women's Fund was established. This was a reflection of the SDPJ's strongly held view that Japan should show repentance on the war. The LDP accepted it as a price of the coalition.

North Korea's Nuclear Issues
　In 1993, another major security challenge emerged――namely, the suspicion of nuclear development by North Korea. Although the United States once considered airstrikes, the crisis was averted by the former President Jimmy Carter's visit to Pyongyang in July 1994, and the Korean Peninsula Energy Development Organization (KEDO) was established to provide North Korea with energy. This was based on the assumption that the North Korean regime could not survive for a long time.
　Nevertheless, it continued to develop nuclear weapons and strengthen missile capabilities at the sacrifice of its people.

Tiananmen Square Incident and Japan-China Relations
　As mentioned above, the Tiananmen Square incident of 1989 coincided with the start of Japan's Heisei era. Although there were hopes of liberalization like the Soviet Union's, they were buried by the crackdown of the incident. Deng Xiaoping, knowing that political liberalization had led to the collapse of the Soviet Union, concentrated on economic development.
　China was temporarily isolated. As there were persistent pro-China groups in Japan which strongly advocated that China should not be alienated, the Kaifu Cabinet lifted the sanctions against China, and the subsequent Miyazawa Cabinet decided to ask the Emperor and Empress to pay a state visit to the country. After that, China came out of international isolation and restarted strong development.

Redefining the Japan-US Security Treaty
　At the end of the cold war, some people argued that the Japan-US security treaty was no longer necessary as the threat from the Soviet Union disappeared. In reality, this argument did not prevail. On the other hand, there were growing calls for reducing the burden of Okinawa, where the presence of the US military bases is concentrated.
　In 1995, the Ryutaro Hashimoto Cabinet reaffirmed the importance of the treaty, known as "redefinition of the Japan-US security treaty," and agreed to relocate US marines in Okinawa Prefecture.
　Regarding Japan-US Security Treaty, the bipartisan Armitage-Nye Report on the post-cold war roles of the US and Japan was issued, and an increasing number of experts in the two countries expected that the division of labor between them should be reviewed, with particular focus on the exercise of the right of collective self-defense.

2. 9/11 and the Search for an Independent Path: 2001-2006

　The 9/11 terrorist attacks in 2001 shook the world. The United States declared war on al-Qaeda and deployed forces to Afghanistan. Major European countries also sent their troops, forming the International Security Assistance Force (ISAF). Japan enacted the Anti-Terrorism Special Measures Law and supported the activities of the US and other countries.
　Around this time, the Koizumi Cabinet came up with a new policy toward North Korea. In September 2002, Prime Minister Koizumi made a surprise visit to Pyongyang and met with Chairman Kim Jong-il of the National Defense Commission of North Korea, the de facto head of the country, and issued the Pyongyang Declaration. In the declaration, Kim Jong-il admitted the abduction of Japanese nationals and promised denuclearization, while Japan pledged assistance after the normalization of diplomatic relations, and the two countries agreed to pursue the goal of the normalization of the relations.
　Soon after, however, it came to light that North Korea was secretly developing nuclear weapons. In Japan, there was a growing outcry of public opinion that North Korea's response to the abduction issue was insufficient. As a result, the negotiations failed to progress after Koizumi's second visit to North Korea in 2004.
　In 2003, the United States launched an attack on Iraq for allegedly producing weapons of mass destruction. While the United Nations Security Council found the US assertion lacking sufficient evidence, the United States decided to start the attack without the council's support. Since cooperation with the United States on North Korea's nuclear issues was vital, Japan supported the US on the Iraq issue and dispatched the SDF to Iraq for the purpose of peaceful reconstruction.
　During this period, Japan's diplomacy toward the UN was noteworthy. In the wake of the Gulf war and many regional conflicts, a series of UN peacekeeping operations (PKO) were established by the UNSC. While Japan is not a permanent member of the UNSC, Japan sometimes had to bear the cost of decisions made by the council in which Japan did not participate.
　Under these circumstances, the opinion that Japan should become a permanent member of the UNSC grew, led by the Ministry of Foreign Affairs. In the early 1990s, although Boutros Boutros-Ghali envisioned a plan to give a united Germany and Japan permanent seats, Japan was not enthusiastic about the idea. Many people had the misperception that if Japan became a permanent member, it would have to assume an extra military roles. There were also people who said that they would not oppose the idea if other countries recommended so. The chairman of a committee that was set up with the intention of considering this problem from cautious perspective was Junichiro Koizumi.
　In 2004, Japan launched a full-scale campaign to reform the UNSC. With the aim of marking the UN's 60th anniversary in September 2005, the G4 (composed of Japan, Germany, India, and Brazil) was formed, and a draft resolution was submitted. However, it failed due to the opposition from the United States and China, and the non-cooperation of African countries.
　The biggest reason for this failure was the lack of a strategic approach. It would have materialized if Prime Minister Koizumi had persuaded Bush and adopted a more flexible stance on the issue of the visit to Yasukuni shrine, which was a point of contention with China. However, Koizumi, once an opponent of the idea of getting a permanent seat in the UNSC, placed more importance on the United States than on the UN. Nevertheless, the UNSC reform movement was a new attempt in Japan's diplomacy, which had always made relations with the United States the top priority.
　Over the DPRK nuclear issue, a number of six-party talks (composed of North Korea, the US, South Korea, China, Russia, and Japan) were held since 2003. Nonetheless, North Korea has secretly continued its nuclear program and long-range missiles development. In 2006, after North Korea conducted a nuclear test, the UNSC adopted a resolution imposing sanctions against it.

3. China's Expansion and Japan's Strengthening of Security Policy: 2008-2015

　While the United States was dragged into the quagmire of the Middle East, China gained strength. In particular, after the Lehman shock, it led the world economy by expanding domestic demand on a large scale. In 2008, when the Olympic game were held in China, it overtook Japan in terms of economic scale. Its growth in military spending also became significant. Since those days, China stopped using such terms as future democratization.　
　In 2010 and 2012, China sent its government vessels into Japanese waters around the Senkaku islands to challenge Japanese territorial rights. In the South China Sea, China claimed sovereignty over an area inside the so-called Nine-dash Line, which includes many high seas and territories of other countries. The Philippines filed a complaint with the Permanent Court of Arbitration, which found the Chinese claim groundless. Nonetheless, China has completely ignored this ruling.
Under the Abe Cabinet, Japan has promoted a number of reforms in its security policy. In 2013, the government formulated the National Security Strategy, established the National Security Secretariat, and reviewed the export policy of defense equipment. In 2014, the government changed its interpretation of the Constitution to allow the partial exercise of the right of collective self-defense, supported by a proposal of the Security Legislation Panel. Based on this, a package of new legislations was enacted in 2015. Although there was a great deal of domestic opposition to this, its content was moderate, below the international standard, and all Southeast Asian countries welcomed it.　Nevertheless, Japan's reinforcement of its security policy has been quite minimal and has failed to keep up with significant changes in the real world.
　On the other hand, one of the criticisms against Japan was on the so-called history issue, over which Japan was accused of being unrepentant about its past. In response to this, Japan-ROK joint studies on history were conducted for two terms from 2002, but no significant progress was made. In 2006, Japan-China joint studies on history was proposed, which made some progress.
　In 2015, Prime Minister Abe released a statement commemorating 70 years since the end of World War II. This statement was appreciated by most countries, including those in Southeast Asia. With the exception of contentions with South Korea, the history issue has passed its critical stage.

4. Summary at the End of the Heisei Era

　Japan's diplomatic environment at the end of the Heisei era is extremely bleak. Its relations with Russia, despite the close personal ties between Prime Minister Abe and President Putin, have made little progress and, in fact, have receded. At the beginning of the Reiwa era, the prospect of having Habomai and Shikotan Islands returned, let alone the return of all four islands as a package, is not good.
　Regarding the relations with North Korea, it has repeatedly conducted nuclear tests and promoted the development of long-range missiles in an attempt to gain recognition from the Trump administration as a nuclear power.
　In South Korea, President Moon Jae-in, who took office in 2016, has not showed the attitude to fulfill the agreement on the comfort women issue and done nothing on its Supreme Court ruling over the so-called former-laborer issue. As a result, Japan-ROK relation is now at their worst since the end of World War II.
　China is moving closer to Japan in response to the Trump administration's aggressive trade policy. However, China's oppression of Hong Kong and the Uighurs continue. Although Japan wants to avoid confrontation, it is impossible to accept China's policies in their entirety.
　Relations with Southeast Asia and India are going well. The Free and Open Indo-Pacific Initiative (FOIP), which was originally called a strategy, has achieved a certain success in containing China's Belt and Road Initiative (BRI). The United States also supports this idea, and European countries such as France and UK are moving toward cooperation.
　Japan's economic power in the world is second only to that of the United States and China, but its share is at one-third of its heyday level. Its average growth rate is around 1%, even with the massive government debt.
　However, Japan is moving in the right direction for now. While sustaining a good relation with the Trump administration, Japan has become a central force in maintaining multilateral cooperation, leading the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP). Today, Japan's foreign and security policies play a crucial role not only for the country but also for the world. While supporting the world order, Japan's role is to strengthen its own defense capability, to focus on economic reconstruction, and to become a bearer of multilateralism.