If you hear the noise of splashing from the halls of Government at the moment, it is the sound of ministers desperately trying to row away from the Iraqi policy and its consequences.

In the last week we have had both the Lord Chancellor, Charles Falconer, and the Attorney General, Lord Goldsmith, in different parts of the world declaring how wrong Guantanamo Bay was: a "shocking affront to the principles of democracy," declared Lord Falconer in Australia, a breach of Article 3 of the Geneva Conventions opined Lord Goldsmith in Chicago.

Didn't say that in public at the time, did they? All those years when Charles Kennedy doggedly raised the question of treatment of British detainees at Prime Minister's Question Time, to be swatted aside by a Tony Blair determined to avoid any hint of criticism of President Bush and a Commons all too ready to jeer at anything as serious as this, we didn't get one solitary voice from the Government or its law officers that this grotesque institution was unacceptable by any international standard of behaviour.

Goldsmith apparently told his friends when first sent to the US by Blair to discuss the detainees that he was "ready to resign" he felt so critical of US behaviour and so concerned to protect British citizens. He did no such thing, of course, exuding not even the faintest whiff of protest when questioned by the press there.

Nor is it any different over Lebanon, an issue on which the Foreign Office minister Kim Howells now says he has regrets, a sentiment which, we are reliably informed, is shared by the Prime Minister and his Foreign Secretary, Margaret Beckett. A bit late now to reveal it, isn't it?

Well, not if all we are witnessing is the sight of the rats leaving the sinking ship of HMS Blair, and the captain himself trying to better his image as he walks down the gangplank to his escape launch. If people despise politicians, as they seem to on all the opinion polls, it is precisely because of this sort of behaviour.

But the question one still has to ask is why did so few speak out let alone resign if, as they now say, they always opposed the policy. Of the whole government, only Robin Cook resigned at the time, to be followed by Clare Short later.

This is not a matter of empty gestures. We have grown so used to the discussion of resignations as part of a battle between government and the press over responsibility for error or scandal, that we forget the importance of resignation as an issue of principle. If only Lord Goldsmith has been man enough to do what he bravely told his friends he was considering and resigned over Guantanamo, the impact would have been devastating.

It would have been impossible for Tony Blair not to have taken up the case of the British internees and voiced British disapproval over the whole US practice. Even more would that have been true if Goldsmith had resigned over his original advice on the legality of the war, when he knew it was wrong but retreated to the lawyer's excuse that it was his job to give the advice most helpful to his client.

And what would have happened if Margaret Beckett had resigned over Lebanon? We know that she disapproved of Blair's policy of standing back and letting Israel do its worst. We know she tried to express that disapproval by making a stand of the side-issue of US overflights to Israel (she was soon silenced on that one).

Had she chosen to resign then, not only would it have been far better for the country, it would have been far better for herself. She would have emerged as a heroine who had expressed the feelings of most in the country and stood by her principles, a real player in the post-Blair configuration, instead of being reduced to a cypher of a Foreign Secretary, as she is now.

We know why ministers don't resign on principle. They're not in politics to make a difference. Otherwise they would be prepared to walk away. They're in it as a career like any other, but with more fringe benefits if you make minister. In an era when politics has become highly professionalised, the route to preferment has lain through keeping close to the centre of power. In that sense politics is now much more like the corporate world, where the scandals of Enron, Shell's oil reserves and BP's safety record have revealed a totality of directors who have preferred silence to objection. The whistleblowers are all well down the hierarchy.

But the government of a nation is not the same as a corporation. We are talking of matters of war and peace, of the happiness or misery of every citizen. It only works if there are at least some ministers prepared to speak up and stake their careers on what they think is right.

a.hamilton@independent.co.uk