Leading article: A mendacious attack by Mr Blair to cover up his fatal misjudgement

For all Mr Blair's personal salesmanship at the time, this began as a highly unpopular war, and it remains one

The Prime Minister used the latest of his "legacy" speeches to share his thoughts on war and peace. His argument was that this country's diplomatic reach would be severely curtailed if we restricted ourselves to such activities as peacekeeping, administering development aid and combating climate change. Britain, he argued, must not fight shy of using military force; for this country, "hard" power will remain as important as "soft".

Now there is room for different opinions about the balance between these different applications of power - the debate Mr Blair belatedly called for. But there was a second strand to his argument on which there is no room for debate at all. In seeking to blame the media for what he sees as the growing distaste of the British public for war, the Prime Minister is quite simply wrong. If there is, as he suggested, a crisis of confidence in the benefits of military force, it is one that he has brought upon himself.

Mr Blair observed, rightly, that modern technology makes it impossible for governments to shield the civilian public from the unpleasant reality of war - as was possible, for instance, during the Falklands war or, to a lesser extent, during the Gulf war. Government censorship, on political or taste grounds, is now almost impossible. As we saw with the execution of Saddam Hussein, eyewitnesses have the means to gainsay the sanitised version. The truth, however gory and dishonourable, will out.

The ready availability of uncensored information, however, is not the only, or even the chief, reason why the British public is less supportive of armed intervention than once it was. Traditionally, the British public has had a strong stomach for military ventures; as a nation, we retain a fierce pride in the professionalism of our armed forces. The public was largely supportive of Mr Blair's justified interventions in Sierra Leone and Kosovo.

There was support, too, for the initial deployment in Afghanistan. Contrary to what Mr Blair said yesterday about the reluctance of opinion to countenance long campaigns, "especially when the account it receives is via a modern media driven by ... pictures", there was a broad understanding that British troops would be in Afghanistan for the long haul.

No, what we are looking at now is not a general crisis of confidence in the use of British military force, fostered by the sensation-driven modern media; it is a particular crisis of confidence precipitated by the débâcle of Iraq. For all Mr Blair's personal salesmanship at the time - the weapons of mass destruction and all that - this began as a highly unpopular war, and it remains one. Rather plaintively, Mr Blair said yesterday that the armed forces wanted public opinion "not just behind them, but behind their mission".

It is astounding that, almost four years on, Mr Blair still fails to understand that the mission is precisely the problem. And his address contained all the old deceits. He conflated, as he habitually does, the interventions in Afghanistan and Iraq, even though the one had UN approval and the other, crucially, did not. He spoke about the qualitatively different threat we face after 9/11, as though the prime reason for invading Iraq was terrorism. And yet again he rejected all suggestion that Britain's presence in Iraq might be a factor in the alienation of young British Muslims.

To this catalogue he has now added the notion that media coverage is turning the British public off the use of "hard" power. The voters may indeed be more wary of military interventions in future. And so may the MPs who represent them. If this is so, however, it will not be because the media have willed it, but because of the fatal misjudgement of a Prime Minister.