September 11 Attacks Remembrance Day

What Is September 11 Remembrance Day?

Every September 11th is remembered in Japan as the day of the "September 11 terrorist attacks" (アメリカ同時多発テロ事件の日, Amerika Dōji Tahatsu Tero Jiken no Hi). On September 11, 2001, coordinated terrorist attacks by the Al-Qaeda organization struck the United States — hijacked aircraft were crashed into the World Trade Center towers in New York City, the Pentagon in Arlington, Virginia, and (following passenger resistance) into a field in Shanksville, Pennsylvania. Approximately 3,000 people were killed — the deadliest terrorist attack in history and the most significant attack on American soil since Pearl Harbor.

Japan's Response to September 11

Japan was deeply affected by the September 11 attacks — both as an ally of the United States and as a nation with its own historical experience of sudden, devastating attacks. Prime Minister Junichiro Koizumi expressed Japan's solidarity with the United States immediately, and Japan subsequently enacted the "Anti-Terrorism Special Measures Law" (テロ対策特別措置法) to enable Japan's Self-Defense Forces to support U.S. operations in Afghanistan — a significant extension of Japan's military cooperation within the constraints of Article 9 of the Constitution. Japan lost 24 citizens in the attacks, including employees of companies with offices in the World Trade Center.

September 11 and Japan-US Relations

The September 11 attacks reinforced the U.S.-Japan security alliance at a critical moment — demonstrating the alliance's importance to both countries in an era of new, non-state security threats. Japan's support for the U.S. response to the attacks, including naval refueling support in the Indian Ocean, was one of the most significant extensions of Japan's security cooperation role since the alliance's establishment in 1951.

Fun Facts

• Japanese victims: The 24 Japanese nationals killed in the September 11 attacks included financial industry professionals, a flight attendant on one of the hijacked planes, and others working in the World Trade Center. Their deaths were commemorated in Japan alongside the thousands of other victims.
• Time zone impact: The September 11 attacks occurred in the early morning U.S. East Coast time, making it evening in Japan — many Japanese watched the attacks unfold on live television in real time as the events developed through the Japanese evening and night of September 11.