Labour leader Jeremy Corbyn has made one of his most controversial appointments yet – Seumas Milne, the Guardian columnist and radical socialist, is his new director of communications and strategy.

Milne, 58, is a vocal critic of western governments. He has written defences of what he regards as the positive aspects of the Soviet Union. He blames Nato for the current Ukraine crisis, not Russia. And he has argued that the US brought 9/11 on itself.

Some of Milne's critics accuse him of being a Stalinist. He is a divisive figure and brings into question Corbyn's commitment to rebuild unity in the Labour party amid infighting between the far-left and moderates. Here are some clippings from Milne's commentary over the years.

On the murder of Lee Rigby by radical Islamists

The videoed butchery of Fusilier Lee Rigby outside Woolwich barracks last May was a horrific act and his killers' murder conviction a foregone conclusion. Rigby was a British soldier who had taken part in multiple combat operations in Afghanistan. So the attack wasn't terrorism in the normal sense of an indiscriminate attack on civilians.

Woolwich attack: If the whole world's a battlefield, that holds in Woolwich as well as Waziristan, 2013

On Nato's role in the Ukraine war and 'defensive' Putin

The reality is that, after two decades of eastward Nato expansion, this crisis was triggered by the west's attempt to pull Ukraine decisively into its orbit and defence structure, via an explicitly anti-Moscow EU association agreement. Its rejection led to the Maidan protests and the installation of an anti-Russian administration – rejected by half the country – that went on to sign the EU and International Monetary Fund agreements regardless.

No Russian government could have acquiesced in such a threat from territory that was at the heart of both Russia and the Soviet Union. Putin's absorption of Crimea and support for the rebellion in eastern Ukraine is clearly defensive, and the red line now drawn: the east of Ukraine, at least, is not going to be swallowed up by Nato or the EU.

It's not Russia that's pushed Ukraine to the brink of war, 2014

On the causes of 9/11

In the aftermath of the first world war, the League of Nations handed out mandates to Britain and France to prepare countries such as Palestine, Iraq and Lebanon for eventual self-government. On the 80th anniversary of the Balfour declaration – in which Britain promised to establish a national home in Palestine for the Jewish people without prejudicing the rights of the Arab inhabitants – it hardly needs spelling out that the long-term fallout was calamitous.

The roots of the global crisis which erupted on September 11 lie in precisely these colonial experiences and the informal quasi-imperial system that succeeded them.

An imperial nightmare, 2001

Certainly, the September 11 atrocity was an unprecedented act of non-state terror. But such groups are also unquestionably the product of conditions in the Arab and Muslim world for which both Britain and the US bear a heavy responsibility, through their unswerving support of despotic regimes for over half a century.

Terror and tyranny, 2001

On the killing of British and US troops in post-Saddam Iraq

What is not in doubt is that the resistance has decisively changed the balance of power in Iraq and beyond. The anti-occupation guerrillas are routinely damned as terrorists, Ba'athist remnants, Islamist fanatics or mindless insurgents without a political programme. In a recantation of his support for the war this week, the liberal writer Michael Ignatieff called them "hateful". But it has become ever clearer that they are in fact a classic resistance movement with widespread support waging an increasingly successful guerrilla war against the occupying armies. Their tactics are overwhelmingly in line with those of resistance campaigns throughout modern history, targeting both the occupiers themselves and the local police and military working for them.

The right to resist, 2003

On communism and the Soviet Union

For all its brutalities and failures, communism in the Soviet Union, eastern Europe and elsewhere delivered rapid industrialisation, mass education, job security and huge advances in social and gender equality. It encompassed genuine idealism and commitment, captured even by critical films and books of the post-Stalin era such as Wajda's Man of Marble and Rybakov's Children of the Arbat. Its existence helped to drive up welfare standards in the west, boosted the anticolonial movement and provided a powerful counterweight to western global domination.

Communism may be dead, but clearly not dead enough, 2006

Disputing the number of deaths for which Stalin was responsible

Not only is it increasingly common for Stalin to be bracketed with Hitler as the twin monster of the modern era, even in the Soviet Union, but in West Germany and Austria a significant "revisionist" academic trend — represented by historians like Ernst Nolte, Andreas Hilgruber, and Ernst Topitsch — goes on to argue that the Stalinist system was actually responsible for the Nazis and the Second World War.

Central to these debates is the issue of the number of Stalin's victims. Controversy about the scale of repression in the Stalin era has rumbled on in Western universities for many years, and has now been joined by Soviet experts who are equally divided. Thames Television, with its 25 million deaths, has opted for the furthest extreme.

Stalin's missing millions, 1990

On trying Slobodan Milosevic in The Hague for the Bosnian genocide

The man long-reviled as the Butcher of Belgrade – or even a quasi-Nazi dictator, despite his regular election victories – has already been convicted in the court of western public opinion, not only for the war crimes charges he now faces, but for a decade of slaughter in the Balkans.

Shamelessly bought with $1.3bn of aid for a country ravaged by sanctions and Nato bombing, Milosevic's extradition had to be forced through by decree, in defiance of Yugoslavia's constitutional court, by a government which knew it stood no chance of getting the decision through parliament.

Hague is not the place to try Milosevic, 2001

On the fall of the Berlin Wall

I think it certainly was surprising that there was so little resistance to what took place. And that's got a sort of positive and a negative side to it. The right-wing always used to say, you know, these communist regimes they only use violence, there'll be a bloodbath. And of course, it was many of the communist leaderships that made these changes themselves. Many of the democratic changes were of course introduced in the Soviet Union by Gorbachev, not by those who replaced him.

Of course there was some violence in places like Romania, and in Russia there was of course quite considerable fighting, not only at the time of the coup in '91, but also in '93 when they laid siege to the parliament. But I think the fact was that there was a group of people in power who saw that they stood to benefit from the restoration of capitalism, and many ordinary people who benefited in many ways from the former socialism there was in eastern Europe didn't really feel ownership of the system, and they didn't necessarily see what was happening or what they could do to stop it.

But if you look at the opinion polls then and even more now, most people in a good number of those countries regret the loss of those benefits and the positive aspects of that system. As you [George Galloway] mentioned, in eastern Germany most people today have a positive view of the former east Germany, the GDR, and regret its passing. Of course, there's some things that they don't regret. They like the fact that they can move freely, which they couldn't before. They can travel freely, that there's more freedom of speech than there was then. And of course, few people mourn the passing of the Stasi, the security police in East Germany. But the huge social benefits that have been lost not only in eastern Germany but across eastern Europe and the Soviet Union, are mourned by the people of those countries – but getting them back is a very different and difficult business.

Of course, 1989 was an important shift and an important loss for many millions of people as well as some gains.

George Galloway and Seumas Milne discuss the fall of the Berlin Wall, 2009