The warmongering and human rights abuses of the New Labour years seem forgotten by all but the likes of Gareth Peirce. Yet Blair’s legacy lingers on in Afghanistan and Iraq and is re-emerging in Syria and Iran.

In the kabuki theatre of British parliamentary politics, great crimes do not happen and criminals go free. It is theatre, after all; the pirouettes matter, not actions taken at remove in distance and culture from their consequences. It is a secure arrangement guarded by cast and critics alike. The farewell speech of one of the most artful, Tony Blair, had "a sense of moral conviction running through it", effused the television presenter Jon Snow, as if Blair's appeal to kabuki devotees was mystical. That he was a war criminal was irrelevant.

The suppression of Blair's criminality and that of his administrations is described in Gareth Peirce's Dispatches from the Dark Side: on Torture and the Death of Justice, published in paperback this month by Verso. Peirce is Britain's most distinguished human rights lawyer; her pursuit of miscarriages of justice and justice for victims of state crimes, such as torture and rendition, is unsurpassed. What is unusual about this accounting of what she calls the "moral and legal pandemonium" following the 9/11 attacks is that, in drawing on the memoirs of Blair and Alastair Campbell, cabinet minutes and MI6 files, she applies the rule of law to them.

Advocates such as Peirce, Phil Shiner and Clive Stafford-Smith have ensured the indictment of dominant powers is no longer taboo. Israel, America's hitman, is now widely recognised as the world's most lawless state. The likes of Donald Rumsfeld now avoid countries where the law reaches beyond borders, as do George W Bush and Blair.

Jackdaw travels

Deploying sinecures of "peacemaking" and "development" that allow him to replenish the fortune he accumulated since leaving Downing Street, Blair's jackdaw travels are concentrated on the Gulf sheikhdoms, the US, Israel and safe havens such as the small African nation of Rwanda. Since 2007, Blair has made seven visits to Rwanda, where he has access to a private jet supplied by President Paul Kagame. Kagame's regime, whose opponents have been silenced brutally on trumped-up charges, is "innovative" and a "leader" in Africa, says Blair.

Peirce's book achieves the impossible on Blair: it shocks. Tracing the "unjustifiable theses, unrestrained belligerence, falsification and wilful illegality" that led to the invasions of Afghanistan and Iraq, she identifies Blair's assault on Muslims as criminal and racist. "Human beings presumed to hold [Islamist] views were to be disabled by any means possible, and permanently . . . in Blair's language a 'virus' to be 'eliminated' and requiring 'a myriad of interventions [sic] deep into the affairs of other nations'." Whole societies were reduced to "splashes of colour" on a canvas upon which Labour's Napoleon would "reorder the world".

The very notion of war was wrenched from its dictionary meaning and became "our values versus theirs". The perpetrators of the 9/11 attacks, mostly Saudis who trained to fly in America, were all but forgotten. Instead, the "splashes of colour" were made blood-red - first in Afghanistan, land of the poorest of the poor. No Afghans were members of al-Qaeda; on the contrary, there was mutual resentment. No matter. Once the bombing began on 7 October 2001, tens of thousands of Afghans were punished with starvation as the World Food Programme withdrew aid on the cusp of winter. In one stricken village, Bibi Mahru, I witnessed the aftermath of a single Mk 82 "precision" bomb's obliteration of two families, including eight children. "TB," Campbell wrote, "said they had to know that we would hurt them if they don't yield up OBL."

The cartoon figure of Campbell was already at work on concocting another threat in Iraq. This "yielded up", according to the MIT Centre for International Studies, between 800,000 and 1.3 million deaths - a figure that exceeds the Fordham University estimate of deaths in the Rwandan genocide.

And yet, Peirce wrote, "the threads of emails [and] internal government communiqués reveal no dissent". Interrogation that included torture was on "the express instructions . . . of government ministers". On 10 January 2002, Foreign Secretary Jack Straw emailed his colleagues to agree that sending British citizens to Guantan­amo Bay was "the best way to meet our counterterrorism objective". He rejected "the only alternative" of repatriation to the United Kingdom. On 6 February 2002, Home Secretary David Blunkett noted that he was in "no hurry to see any individuals returned to the UK [from Guantanamo]". Three days later, the Foreign Office minister Ben Bradshaw wrote: "We need to do all that we can to avoid the detainees being repatriated to the UK." Not one of the people to whom they referred had been charged with anything; most had been sold as bounty by Afghan warlords to the Americans.

Death by misadventure

Immersed in its misadventure and lies, listening only to their leader's crooned "sincerity", the Labour government consulted no one who spoke the truth. Peirce cites one of the most reliable sources, the Conflicts Forum, run by the former intelligence officer Alastair Crooke, who argues that, to "isolate and demonise [Islamic] groups that have support on the ground, the perception is reinforced that the west only understands the language of military strength". In wilfully denying this truth, Blair, Campbell and their echoes planted the roots of the 7/7 attacks in London.

Today, another Afghanistan and Iraq beckon in Syria and Iran, perhaps even a world war. Once again, voices such as Crooke's attempt to explain to a media salivating for "intervention" in Syria that the civil war in that country requires skilled and patient negotiation, not the provocations of the British SAS and the familiar bought-and-paid-for exiles who ride in Anglo-America's Trojan horse.