Maurice Robert "Mike" Gravel (; born May 13, 1930) is an American politician who was a Democratic United States Senator from Alaska from 1969 to 1981 and a candidate in the 2008 U.S. presidential election. Born and raised in Springfield, Massachusetts, by French-Canadian immigrant parents, Gravel served in the U.S. Army in West Germany, and he later graduated from the Columbia University School of General Studies. He moved to Alaska in the late 1950s, becoming a real estate developer and entering politics. He served in the Alaska House of Representatives from 1963 to 1966 and also became Speaker of the Alaska House.

In the late 1960s and early 1970s the U.S. Department of Defense was in the process of performing tests for the nuclear warhead for the Spartan anti-ballistic missile. Two tests, the "Milrow" and "Cannikin" tests, were planned, involving the detonation of nuclear bombs under Amchitka Island in Alaska. The Milrow test would be a one megaton calibration exercise for the second, and larger five megaton, Cannikin test, which would measure the effectiveness of the warhead. Gravel opposed the tests in Congress. Before the Milrow test took place in October 1969, he wrote that there were significant risks of earthquakes and other adverse consequences, and called for an independent national commission on nuclear and seismic safety to be created; he then made a personal appeal to President Nixon to stop the test.  After Milrow was conducted, there was continued pressure on the part of environmental groups against going forward with the larger Cannikin test, while the Federation of American Scientists claimed that the warhead being tested was already obsolete. In May 1971, Gravel sent a letter to U.S. Atomic Energy Commission hearings held in Anchorage, in which he said the risk of the test was not worth taking. Eventually a group not involving Gravel took the case to the U.S. Supreme Court, which declined to issue an injunction against it, and the Cannikin test took place as scheduled in November 1971. Gravel had failed to stop the tests (notwithstanding his later claims during his 2008 presidential campaign).  Nuclear power was considered an environmentally clean alternative for the commercial generation of electricity and was part of a popular national policy for the peaceful use of atomic energy in the 1950s and 1960s. Gravel publicly opposed this policy; besides the dangers of nuclear testing, he was a vocal critic of the Atomic Energy Commission, which oversaw American nuclear efforts, and of the powerful United States Congress Joint Committee on Atomic Energy, which had a stranglehold on nuclear policy and which Gravel tried to circumvent. In 1971, Gravel sponsored a bill to impose a moratorium on nuclear power plant construction and to make power utilities liable for any nuclear accidents; in 1975, he was still proposing similar moratoriums. By 1974, Gravel was allied with Ralph Nader's organization in opposing nuclear power.  Six months before U.S. Secretary of State Henry Kissinger's secret mission to the People's Republic of China (P.R.C.) in July 1971, Gravel introduced legislation to recognize and normalize relations with China, including a proposal for unity talks between the P.R.C. and the Republic of China (Taiwan) regarding the Chinese seat on the U.N. Security Council. Gravel reiterated his position in favor of recognition, with four other senators in agreement, during Senate hearings in June 1971.

Using a quote from the above article, answer the following question: What was he doing during the Cold War?
Gravel opposed the tests in Congress.