Will the US now attack Tehran?

If you think that even George W Bush would not be foolish enough to start a war in Iran, think back to how unlikely an invasion of Iraq seemed three years ago. The prologue is uncannily similar: the claims that a member of the "axis of evil" is developing nuclear weapons and that it supports terrorist movements overseas; the demands for inspections; the growing references among Washington conservative commentators to the desirability of "regime change". True, Iran is closer to acquiring a nuclear bomb than Iraq was and, as a country openly dedicated to Islamic crusades and to the destruction of the Great Satan, poses a more plausible threat than Saddam Hussein. But would Iran be a significant crisis at all if the British and Americans had refrained from invading Iraq?

Imagine that you are one of the ruling mullahs in Tehran. You know that your main regional enemy, Israel, has nuclear weapons, though it has never admitted it. You know its ally, the US, is also a nuclear power and it has already invaded your neighbour and overthrown its government on the flimsiest of pretexts. You know that both the US and its ally, Britain, believe themselves to be at war. You know that the former has a record - Laos, Cambodia - of attacking countries that are thought to supply insurgents against a US-backed government, as you are now accused of doing in Iraq and the West Bank. You know that it believes in pre-emptive strikes, as does Israel. You know also, however, that the Americans have heavy military commitments in Iraq and Afghanistan and that, for the moment, they probably can't mount a successful attack. And you know that the US and UK governments have so diminished their credibility that, when they say you are a threat, neither their voters nor other world leaders will necessarily believe them. Wouldn't you think it best not only to acquire nuclear weapons, but to do so in pretty short order, before what looks like a window of opportunity shuts?

You may be miscalculating, but that isn't the point. The Iraq war and occupation have introduced dangerous uncertainties into world affairs. Instead of the Middle East being stabilised, all the pieces have been thrown into the air - as the Washington neoconservatives hoped they would be. The argument for acquiring nuclear weapons, just in case, has never looked stronger. That, after all, is the argument the existing nuclear powers use to justify holding on to their weapons, despite promises of disarmament. The US has even withdrawn from the test ban treaty, and talks of new circumstances in which it might use nuclear weapons either pre-emptively or during conventional wars. As seven foreign ministers (Brazil, Egypt, Ireland, Mexico, South Africa, New Zealand and Sweden) have observed, in a joint declaration this month, the established nuclear powers clearly see their weapons as "a security enhancer". Is it surprising that others think such weapons might enhance their security, too? Given that Israel is the region's only nuclear power - and also spends more than twice as much on defence as its five closest neighbours combined - a conciliator from Mars might conclude that the planet's best hope is to allow Iran to get the bomb, even to give it a helping hand. Only one thing is worse than a balance of terror: an imbalance of terror.

A covert attempt at regime change may be thought too slow and uncertain to head off the threat of a nuclear Iran, a direct military attempt too difficult and bloody. That leaves the option of a pre-emptive strike on Iran's nuclear facilities. The CIA, it is said, has done war games on the results. Nobody liked them. Don't assume the strike won't therefore happen. President Bush, after all, ignored the CIA's advice on Iraq.

Take the risk of losing votes

It is unfair to say the Labour Party has ceased entirely to be a crusade: this government's battle against poverty, its creation of the child trust fund, its attempts to cut NHS waiting lists should all create ripples in the social-democratic bloodstream, if not exactly stir it with excitement. But as Richard Reeves writes on page 42, new Labour's approach is essentially technocratic. The ideas (where they exist at all) are uninspiring, and so are the policies. "Public value" (see James Crabtree, page 54) sounds admirable, but they won't be talking about it in the Barnsley pubs, even if anyone can explain what it is. Nor are people likely to text their friends about modernisation, devolution and public service reform. Only a ban on hunting and a war in Iraq have created excitement. Yet neither seems central to a social-democratic project.

So here are two ideas for the next election manifesto that might just galvanise the debate. The first is land reform, for which we launched a campaign last week; this week, Christopher Huhne explains how a tax on land value could work (page 38). The second is arms exports. These - according to a new report from the British American Security Information Council, the Oxford Research Group and Saferworld - are subsidised by the taxpayer to the tune of at least £453m a year, and possibly as much as £936m. Aside from the moral arguments, this is money badly spent. Far from providing jobs, the report concludes, the arms industry keeps skilled workers away from more profitable and worthwhile enterprises.

These two issues could engage Labour's traditional supporters and activists. New Labour thinks it can do without such people. But engagement in politics ripples outwards: without a core of enthusiasts, without issues that people can talk about in homes and workplaces, the votes will get fewer and fewer. Some will oppose both our ideas - and indeed they might lose Labour a few votes. But if that is the price of revitalising democratic politics, it is one worth paying.