Of all the evasive arguments over the replacement of Trident, I find the “we don’t need to take a decision now” position the most dishonest. That it is the official stance of the Liberal Democrats shows just how pathetic that party has become.

The first bit of sophistry is the argument that today’s vote isn’t really about “replacing Trident”, but is about replacing the submarines that fire them. As if the submarines are much use for anything else. Alongside that, I would put Tony Blair’s demand that Trident’s opponents “need to explain why disarmament by the UK would help our security”. No they don’t. Mr Blair needs to explain how replacing Trident makes us more secure. Does anyone honestly believe that a leader crazy enough to fire a nuclear weapon at us would care whether we could fire one back at him?

The greatest nuclear threat we face is anyway not from a national leader but from stateless terror. Osama bin Laden has already tried to buy a nuclear bomb and I don’t suppose he has given up. Wouldn’t we be better off investing in the security of chaotic nuclear facilities around the world than buying more bomb power in Britain? Only last week the head of the Democratic Republic of Congo’s dilapidated nuclear reactor plant was arrested on suspicion of selling off unknown quantities of enriched uranium — nobody knows to whom. I imagine nothing would please a jihadist more than Britain retaliating against a nuclear attack by firing a nuclear missile at a Muslim country. The thought that we could retaliate like that would make us an even more tempting target.

I would never, ever, ever want a British leader to fire a nuclear weapon. Ever. In any circumstances. Even if someone fired one at us. Even if a country fired more than one at us. I do not believe that responding with equal terror and carnage against other citizens, other families, would ever be the right thing to do. So perhaps for me the argument is simpler than it is for the tomahawks among you.

But can somebody tell me, how has our nuclear deterrent made us safer over the last two decades? Is Norway, is Argentina, less safe than the UK? Do you feel safer in London than in Lisbon? The Secretary of State for Defence, Des Browne, claimed at the weekend: “It’s not nearly as straightforward as people suggest. They sleep soundly in their beds at night because we have nuclear weapons.” What a pathetic argument; what highly enriched rot. Many of us would feel safer without them. So, Prime Minister, answer me this: can you think of another way to help our security, other than by spending £20 billion on new submarines?

I can. I can think of trying to engage with the Muslim world instead of using the bully-boy tactics of bombing and threatening it. I can think of unlinking our foreign policy from that of the United States to enable us to take some — some — defence decisions alone. I can think of leading by example and reducing our nuclear firepower as a step towards complete disarmament, to encourage other states not to develop theirs. I can think of using our fabled influence with the US to press for disarmament, not rearmament.

I know what you are saying, because I sat in a meeting at The Times yesterday and heard my colleagues saying it about Neil Kinnock. He had “reverted to type” by backing the rebel amendment on Trident, they sneered. He had forgotten why he had to impose discipline over nuclear weapons on Labour in the first place; he was “grovelling to his left-wing friends”.

I have been at The Times long enough not to be surprised at any amount of snickering either at Lord Kinnock or at the antinuclear lobby. What does strike me, however, is how long it is since I have heard any of the pro-nuclear lobby question their own assumptions. I would like to hear them debate whether a weapons system designed to strike at Russian cities in the Cold War is still the right system for a 21st-century stateless conflict in which we need to win hearts and minds, and to explain to me how you do that with bombs. I’d like to know when they think the guns and missiles are going to start persuading people to believe in Western-style democracy in Iraq, in Afghanistan, in the Middle East.

Back to Mr Browne at the weekend: “Some people feel they are prisoners of the position that the party had before it changed in the 1980s.” What patronising rubbish: the prisoners of entrenched positions are our leaders at Westminster, groomed by Labour’s experience in the 1980s to believe it a political imperative to look “strong on defence”. Yet we sceptics are hardly an extreme minority: a poll for The Times in December found that only 52 per cent of people backed the missile system’s replacement. Just above half of us — that is far from an overwhelming mandate for the arguably pointless, even dangerous, expenditure of £20 billion on a load of vile bombs we never want to see used.

Couldn’t Gordon Brown, or David Cameron, or David Miliband or some other senior figure have had the guts to question whether replacing Trident is really necessary? Could the Liberal Democrats not bring themselves to oppose it outright? Mr Blair did not dare give the Cabinet a chance even to debate the decision openly: the White Paper proposing Trident’s replacement was shown to journalists last December, an hour and a half before the Cabinet held its meeting to “discuss” it.

So at least there is a debate to look forward to in the House of Commons today. What a pity, though, that it appears to be a foregone conclusion; that the vote has been passed before the debate begins. What a democracy. What a shame.

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