Tony Blair’s role in waging war against Iraq in 2003 has returned to haunt the ruling elite in Britain—nowhere more so than in the ranks of the Labour Party.

In a Sunday interview with CNN, the former Labour prime minister continued to defend the Iraq war, but did so in terms that only prove it was an illegal war of aggression. He apologised “for the fact that the intelligence we received was wrong” on Iraq’s supposed possession of weapons of mass destruction (WMD) and for “some of the mistakes in planning and certainly our mistake in our understanding of what would happen once you removed the regime.” But he found it “hard to apologise for removing Saddam.”

Blair’s statement goes to the heart of the criminality of the war waged by the US and Britain. Falsely portrayed as a response to the threat posed by Iraq’s WMDs, it was in reality an unprovoked war for regime change and therefore illegal under international law. The International Military Tribunal at Nuremberg, held to examine the war crimes of the Nazis, called the waging of an aggressive war “not only an international crime; it is the supreme international crime, differing only from other war crimes in that it contains within itself the accumulated evil of the whole.”

Blair still wants to maintain the lie that he and then US President George W. Bush genuinely believed that Saddam Hussein was a threat to peace. But evidence to the contrary is now overwhelming.

US General Wesley Clarke has admitted that just 10 days after the September 11, 2001 attack on the World Trade Center, he was told by a general in the Pentagon, “We’ve made the decision we’re going to war with Iraq.”

A few weeks later, with the US at war with Afghanistan, Clarke asked the same general, “Are we still going to war with Iraq?” He replied, “I just got this down from upstairs [the secretary of defence’s office] today… that describes how we’re going to take out seven countries in five years, starting with Iraq, and then Syria, Lebanon, Libya, Somalia, Sudan and, finishing off, Iran.”

Blair himself was directly implicated in the plan to launch an unprovoked attack on Iraq. Just one week before he appeared on CNN, the Mail on Sunday published a memo from then US Secretary of State Colin Powell to Bush. Written on March 28, 2002, it proved that while Blair was formally committed to diplomacy, he had agreed to play the key role in efforts to line up reluctant European powers behind the war, possibly get United Nations backing and seek to shift public opinion. Blair, Powell told Bush, “will be with us should military operations be necessary” and “will present to you the strategic, tactical and public affairs lines that he believes will strengthen global support for our common cause…”

It was to this predetermined end that intelligence dossiers produced by the UK were concocted, justifying war based upon claims known to be false that Iraq possessed chemical and biological weapons of mass destruction and had restarted its nuclear programme.

In 2009 Blair made a more telling admission to the BBC than anything he said on CNN. When asked whether he would have invaded Iraq “if you had known then that there were no WMDs,” he replied, “I would still have thought it right to remove him [Saddam Hussein]… I mean obviously you would have had to use and deploy different arguments about the nature of the threat.”

The 2003 invasion of Iraq and subsequent occupation claimed over 1 million lives and turned over 5 million Iraqis into refugees from a decimated country. Millions of people in the UK, US and throughout the world want Blair, Bush, Powell and their co-conspirators to face war crimes charges. Little wonder then that the Labour Party is desperate to distance itself from Blair’s toxic political legacy.

There are those who claim they were deceived by the prime minister. Andrew MacKinlay, for example, who sat on the foreign affairs select committee, now says “myself and the British people, all of us, were duped.”

Far more important than such self-serving and implausible statements is the claim that the election of Jeremy Corbyn, with a personal history of opposing military interventions, including Iraq, marks a new chapter in Labour’s history. Corbyn has even suggested that Blair “could be” tried for war crimes over Iraq.

Yet the fact remains that Blair walks free, and has even made tens of millions of pounds as a result of his crimes. This is because he did not act as an individual but as the representative of British imperialism and leader of one of its key political instruments, the Labour Party.

It was Labour, and not simply Blair, which backed the second war in Iraq, just as it did the first in 1990, and as it did in Kosovo, Sierra Leone and Afghanistan. Labour MPs did so not because they believed the threat posed by WMDs—millions of people saw through Blair’s lies—but because the party has been shaped by its pro-capitalist programme and decades-long history of defending the interests of British imperialism.

MPs voted with Blair because they shared his central aim of securing the global interests of the British bourgeoisie through a military alliance with Washington. Indeed, the issue remains so politically sensitive that in 2012, then Attorney General Dominic Grieve upheld the 2009 veto by then Justice Secretary Jack Straw of any disclosure of Cabinet meeting minutes from 2003 when Iraq was discussed.

In 2011, just 11 Labour MPs voted against participation in the war against Libya, with supporters employing identical “humanitarian” rhetoric as was used to justify the devastating assault on Iraq.

The election of Corbyn changes nothing fundamental in this regard.

History records that any leader who is seen to conflict with Labour’s fundamental imperialist orientation either faces being replaced, as was George Lansbury in 1935 at the instigation of the Trades Union Congress, or will be obliged to abandon their pacifist pretensions as did Michael Foot in 1982 over the Falklands/Malvinas.

Labour is even now preparing for war once again. Up to a hundred Labour MPs are expected to back extending participation in US-led bombing in Iraq—already agreed in September 2014—to include Syria when it is proposed by the Conservative government. And it is Corbyn who has made this possible, first by nominating a majority of pro-war MPs to his shadow cabinet and then by promising a free vote on whether to back a Syrian intervention. It is on this basis that he should be judged.

For all those wanting justice for the crimes of British imperialism, the central issue is to understand that this is a task inseparably bound to the political mobilisation of the working class against militarism and war on a socialist and internationalist programme. This is a struggle that can only be waged in opposition to the Labour Party, whoever stands at its head.