Leading article: Ill-conceived adventures abroad that cost governments dear at home

Not a day has gone by without some adverse development that has its origin in our ill-considered intervention

For anyone who might have missed salient developments in US and British involvement in the Middle East and the wider region over the past three years, this week has supplied a rapid revision course. Let's take events in reverse order.

Today, thousands will march in Manchester to protest against the Government's foreign policy: accusations range from Mr Blair's delay in calling for a ceasefire in Lebanon, to the closeness of his relations with the United States, to the armed interventions in Afghanistan and Iraq. Staged on the eve of the Labour Party conference, it is confidently expected to be the biggest such event ever held in Manchester.

Yesterday saw the first appearance of the Hizbollah leader, Sheikh Hassan Nasrullah, since the ceasefire was declared in Lebanon five weeks ago. Addressing a mass rally in the heavily damaged southern suburbs of Beirut, he declared that Hizbollah had won a "divine victory". If anyone doubted the counterproductive effect of Israel's bombardment on Hizbollah's support and morale, here was proof. The ceasefire may be holding, but the repercussions - for Israel's image and for the balance of power in the region - will be lasting.

The previous day, a United Nations report stated that human rights in Iraq were in a worse state now than they had been when Saddam Hussein was in charge, with torture as prevalent, if not more so, than before. Given that the cruelty of Saddam Hussein's regime was cited as the second major justification for the US and British intervention - after the threat from (non-existent) weapons of mass destruction, this is an outcome that exposes the truly catastrophic folly of the enterprise.

In the United States, meanwhile, the principled stand of Senator John McCain, combined with pre-election trepidation in Congress, forced President Bush to make concessions to his own Republican Party over the treatment of suspected terrorists. The compromise means that the administration has stopped short - just - of renouncing the Geneva Conventions. But it still leaves the CIA with far more latitude in its interrogation techniques than should be acceptable in a constitutional democracy.

As if this was not enough, a slew of reports from Afghanistan illustrated how far US and British intervention has gone awry. An urgent Nato appeal to member states for reinforcements received no response, save for the slightly accelerated arrival of a Polish contingent. Then, even as a senior British officer claimed that British casualties were far higher than official figures suggested, the Defence Secretary, Des Browne, had the effrontery to admit "surprise" at the level of Taliban resistance. Apparently all the questions raised at the outset about the true nature of the operation, had provoked not a sliver of doubt in his department.

Not a day has gone by without some adverse development that has its origin in our ill-considered or poorly executed foreign intervention. What unites the marchers in Manchester today is the view that the Blair government has been on the wrong side of pretty much every conflict it has entered in the name of George Bush's "war on terror".

The disaffection of Labour's rank and file on foreign policy will make itself felt at next week's party conference, and the extent to which Iraq hobbles British diplomacy is ever more apparent. In the United States, Mr McCain's opposition showed how far Mr Bush now faces real limits on his own, and America's, power.

In sum, this week offers more than a revision course. It has supplied a whole instruction manual on how to lose friends and alienate people, while paying a high price in blood, treasure and national dignity, for the privilege.