Ichirō Ozawa has been a member of the House of Representatives since 1969, in addition to other political roles including Minister of Home Affairs (1985-1986) and leader of the main opposition party, the Democratic Party of Japan (民主党, DPJ) (2006-2009).
Ozawa is known for his leadership in passing the Act on Cooperation with United Nations Peacekeeping Operations and Other Operations in 1992, which was created to send the Self-Defense Forces abroad to participate in the UN’s Peacekeeping Operations.
He has been affiliated with several political parties throughout his career, originally belonging to the Liberal Democratic Party (自民党, LDP) and subsequently co-founding the Japan Renewal Party (新生党), and serving as president of the New Frontier Party (新進党), the Liberal Party (自由党), and the DPJ. In protest against the DPJ, he founded the People's Life First (国民の生活が第一) in 2012, which took many forms until Ozawa joined the Democratic Party For the People (国民民主党, DPFP) in 2019. In 2020, he joined the new Constitutional Democratic Party of Japan (立憲民主党, CDP) in a merger of that party with the DPFP.
In 1999, Ozawa published a partial draft for the constitution. Ozawa holds that the current constitution was created under foreign occupation and does not reflect the views and history of Japan, and that a constitution created under an occupation is invalid. He also states that the Preamble should be rewritten; the emperor should be declared the head of state; Japan must revise Article 9 to permit the right of self-defense; the UN should establish military forces and Japan should contribute to the UN activities, including its military forces. In addition, Ozawa proposes revising the notion of "public welfare (公共の福祉)," to include provisions for new human rights; abolishing the House of Councillors' elections, drastically revising Chapter 4 of the constitution regarding the Diet; establishing a court of justice for constitutional revision; and revising the procedure for constitutional revision.
Although Ozawa has insisted that Japan should be able to exercise its collective self-defense right since the 1990s, he was opposed to the legislation of the security bills by the Abe administration in 2015. Ozawa criticized the government for setting the conditions that require Japan to actually exercise its collective self-defense right as being too obscure; he argued that the government could arbitrarily extend the conditions (2014 interview).