The 1974 campaign of atmospheric nuclear tests was a seven shot series conducted at Mururoa atoll. The primary objectives of the campaign were to begin testing of experimental nuclear devices for eventual use in a MIRV capable missile, begin developmental tests for a warhead which would arm an eventual air-to-surface missile, test small yield tactical weapons, study the effects of small yield tactical weapons, and air drop a tactical nuclear weapon from an aircraft. The series also featured two safety tests.

Weather conditions for this series became increasingly uncooperative, resulting the several delays for shots, reducing the amount of time between each test. The activation of maritime and air danger zones was conducted on 11 June and lasted until September 17. Even though several shots in this series were considerably more powerful then the 1973 series, the exclusion zones around Mururoa and Fangataufa were not modified.[5]

The most dangerous risk involving commercial aircraft was the possibility of pilot blindness being caused by direct visibility of the detonations. As a result, diversion routes away from the exclusion zones were made with Air France and Lan Chile airlines for the 1974 campaign. Only the safety blockhouses on Tureia were maintained for this campaign.[5]

On 2 April 1974, French President Georges Pompidou died suddenly from Kahler's disease after serving 5 years in office. Following his death, Presidential elections were held. Running for office were Giscard d'Estaing of the Independent Republican Party and Francois Mitterand of the Socialist Party.

Giscard d'Estaing was a strong critic of the atmospheric nuclear tests and advocated a permanent switch to underground nuclear testing. Mitterand narrowly lost to d'Estaing in the Presidential elections, however, he received the majority of the vote in French Polynesia (51.23%).[2] On 8 July 1974 d'Estaing's newly appointed cabinet put into motion the goal of abandoning atmospheric nuclear tests in favor of underground testing. This decision effectively set the nuclear weapons research program back at least two years. [4]

The 1974 trials marked the end of France’s atmospheric nuclear testing campaign in the South Pacific. Vigorous protests against the nuclear tests from a number of countries in the South Pacific increased with the announcement of every nuclear testing campaign. Much of this political pressure to stop testing came from the governments of Australia and New Zealand, as well as environmental organizations such as Greenpeace. The protests from the Greenpeace organization became a dramatic symbol of the worldwide view shared on France’s atmospheric nuclear testing campaign in the South Pacific.

Giscard d'Estaing announces the end of atmospheric nuclear testing (25 July 1974)

The planning and preparation for the 1974 series was already underway prior to d'Estaing's election. Since the series featured extensive weapons effects objectives, including an air drop of a nuclear device, underground testing was not a possibility; nor was the cancellation of the series. On 25 July 1974, well after the nuclear testing began, d'Estaing publicly announced that this series would be the last conducted in the atmosphere in French Polynesia.

The 1974 series continued the proof testing the TN-60 warhead. This series also featured the first tests of the TN-70 and weapons development related tests of the new TN-80 warhead. A Jaguar A conducted France’s third and last nuclear air drop on 26 July 1974.

The TN-70 warhead was France's first MIRVed nuclear weapon, the development of which began in 1972. The TN-70, which had a nominal yield of 150 kilotons, had a lower weight and higher survivability than the TN-60. Six TN-70s armed each M-4 SLBM.

The TN-80 was a miniaturized and hardened nuclear warhead for the ASMP air-surface missile, which were deployed on the Mirage IV, Super Etendard, and later the Mirage 2000N. The TN-80 was roughly similar to the TN-70 in terms of technical sophistication, though it had a higher nominal yield of 300 kilotons. The TN-80 entered service in 1985.