His third term began in 1970 by co-sponsoring the McGovern-Hatfield resolution to limit military intervention in the Vietnam War. During this time Harold Carswell was seeking appointment to the U.S. Supreme Court. Muskie voted against him and Carswell failed the confirmation process. Muskie also proposed a six-month ban on domestic and Soviet Union development of nuclear technologies to taper the nuclear arms race.As chair of the congressional environmental committee, he and fellow committee members including Howard Baker introduced the Clean Air Act of 1970, which was co-written by the committee's staff director Leon Billings and minority staff director Tom Jorling. As part of the act, he told the automobile industry it would need to reduce its tailpipe air pollution emissions by 90% by 1977. He also co-wrote amendments to the Federal Water Pollution Act, more commonly known as the Clean Water Act, and urged his fellow Congress members to adopt it, saying "The country was once famous for its rivers ... But today, the rivers of this country serve as little more than sewers to the seas. ... The danger to health, the environmental damage, the economic loss can be anywhere." The bill enjoyed bipartisan support in the U.S. Congress and was passed by the House on November 29, 1971 and the Senate on March 29, 1972. While congressional support was enough to enact it into law President Richard Nixon exercised his executive veto on the bill and stopped it from becoming law. However, after further campaigning by Muskie, the Senate and House of Representatives passed the bill 247–23 to override Nixon's veto. The bill was historic in that it established the regulation of pollutants in the federal and state waters of the U.S., created extended authority for the Environmental Protection Agency, and created water health standards. Also in 1971, Muskie was asked to join the Senate Foreign Relations Committee; he traveled to Europe and the Middle East in this capacity.