Reaffirming his commitment to retain the Trident system and use it if necessary, Mr Blair said: "I believe in the nuclear deterrent."
Publication yesterday of Labour's defence and foreign affairs policy confirmed how the Labour leader has defused defence as an election issue.
Mr Blair refused to forecast the circumstances in which the deterrent would be used. Pressed about the responsibility it represented, he said: "I regard it as awesome".
Introducing his section of A Fresh Strategy for Britain, Labour's defence spokesman, David Clark, said: "We will retain the British nuclear deterrent, Trident. When satisfied with verified progress towards our goal of a global elimination of nuclear weapons, we will ensure British nuclear weapons are included in such negotiations."
Dr Clark said Labour would continue the Government's commitment to limit the number of British Trident warheads to 192 - three per missile on four submarines.
Labour will also remain committed to Nato, to building up the role of the Western European Union as its European arm, oppose plans to give the EU a military role and continue to offer the UK's services for international peace-keeping.
Its most radical proposals yesterday related to the reform of the UN and increasing its ability to respond to crises.
Robin Cook, the shadow Foreign Secretary, stressed the inter-dependence of foreign and security policy and foreign aid. "We make a big mistake if we imagine that foreign policy is less important to Britain because we are no longer a global power. It is even more important for our prosperity and security in the modern world that Britain pursues an active foreign policy," he said.
He repeated Labour's opposition to giving up Britain's seat on the Security Council in favour of an EU representative.
Mr Cook said: "There must be a broadening of the Security Council to make it more representative of the world". But asked whether Germany should get a permanent seat, he said an additional German seat would increase the existing imbalance in favour of old European powers.
The document repeated Labour's formula that a single European currency "could produce significant benefits", while omitting the Labour leadership's usual qualification that it would require the consent of the British people in a referendum or a general election.
After a fierce internal battle between Joan Lestor, spokeswoman on development issues, and Gordon Brown, the shadow Chancellor, it contained a promise only to "start to reverse the decline in UK aid spending", with no timetable.
8 A Fresh Start for Britain: Labour's Strategy for Britain and the Modern WorldReuse content