French President Nicolas Sarkozy announced a modest cut Friday in France's nuclear arsenal, to less than 300 warheads, and urged China and the United States to commit to no more weapons tests. In his first major speech as president on France's much-vaunted nuclear "strike force," Sarkozy said atomic weapons remain a vital component of French defenses. "It is the nation's life insurance policy," he said. He noted that while France does not face a foreseeable threat of invasion, other dangers exist. He singled out Iran's development of its missile forces and the "grave suspicions" surrounding its nuclear program - which France and other western powers fear is aimed at developing weapons. "The security of Europe is at stake," Sarkozy said. Many of France's nuclear weapons are carried aboard submarines, with the rest on warplanes. Sarkozy said the airborne component would be cut by one-third. "After this reduction, our arsenal will include less than 300 nuclear warheads," he said. "That is half the maximum number of warheads that we had during the Cold War." Sarkozy did not say how many warheads France currently has and the Defense Ministry said that information is a state secret. The Federation of American Scientists, which tracks nuclear arsenals around the globe, said in a status report for 2008 that France had 348 warheads. Since Sarkozy is France's first leader born after World War II, his reaffirmation of the need for nuclear weapons, despite France's budgetary difficulties, was significant - marking a continuation of French policy despite a generational shift in political leadership. Sarkozy was speaking at the inauguration of a nuclear submarine named "The Terrible," the fourth in a new generation of French subs, both powered by a nuclear reactor and equipped to carry nuclear missiles. Quieter and more stealthy than its predecessors, "The Terrible" will carry the new M51 nuclear missile with multiple warheads and a longer range than current missiles. France's airborne nuclear weapons are carried by three Air Force squadrons of Mirage 2000N and another Navy flotilla of upgraded Super Etendard jets. They are all to be replaced by high-tech Rafale jets, in Air Force and Navy versions. Sarkozy followed his announcement of weapons cuts with appeals for other nations to scale back their nuclear facilities. He appealed to China and the United States to ratify a nuclear test ban treaty they signed in 1996. "It's time to ratify," he said. He urged nuclear powers to dismantle nuclear test sites. He also called for negotiations on a treaty to ban short- and intermediate-range ground-to-ground missiles and a treaty to ban the manufacturing of fissile material for nuclear weapons. Nuclear deterrence expert Bruno Tertrais said Sarkozy's nuclear policy was largely a continuation of his predecessor's - although Jacques Chirac was not so open about the number of warheads in the French arsenal. "Chirac did not believe that transparency was worthwhile or interesting," said Tertrais, a senior research fellow at the Foundation for Strategic Research think-tank. "There is more continuity than change, but the level of transparency now is something new."