Last Thursday (24 March) US President Barack Obama visited a memorial to the victims of Argentina's so-called 'dirty war'. He made a speech at the Parque de la Memoria, a monument to the thousands who died in the 1970s and 1980s, in which he expressed regret for the role of the United States in the period of severe government repression by the US-backed military junta.

'The United States, when it reflects on what happened here, has to examine its own policies as well, and its own past,' Obama said.

What happened in Argentina was that a military dictatorship was given carte blanche by the US to violently suppress political opposition in the name of 'anti-communism' – a doctrine of almost limitless scope. Cold Warriors, like the then-US Secretary of State Henry Kissinger, may have professed a detestation of communism, but they had more in common with the Stalinists than they perhaps realised. For the Kissingers of the world, as for the communists, a pile of bloated corpses was ultimately worth it if the right side came out on top in the struggle between East and West.

Earlier last week Obama also paid a flying visit to Cuba, another Latin American nation long-overdue an apology on the part of America's political establishment. Fidel Castro is a brutal communist dictator; yet he wasn't wrong when he pointed out that the US had in the past behaved abominably towards Cuba. The Castro regime has immiserated the people of Cuba of its own accord; but that in no way lets America off the hook for its past acquiescence in armed attacks on Cuba by anti-Castro mercenaries, including the 1976 bombing of a Cuban passenger plane.

Along with Argentina and Cuba, Obama might also have stopped off to proffer American apologies to the people of Chile, El Salvador, Brazil and Nicaragua for the crimes inflicted on their peoples by past American administrations.

The history of disastrous 20th century American interventions in Central and South America is a subject worthy of consideration in its own right. But it is also interesting in another respect: the lack of a violent retaliatory response on the part of, say, justifiably aggrieved South Americans, undermines arguments that today seek to exculpate Islamist terrorists as acting in response to American foreign policy. If, as one writer for Salon put it last week, we "brought Brussels on ourselves", why has violent and repressive Western policy in Central and South America not brought similar vengeance upon Western heads?

The answer of course is ideology. Western foreign policy may have helped to create a set of conditions in Iraq propitious to the growth of Islamic State – a weak central government, rampant Shia sectarianism, botched de-Bathification – but Islamist ideology has a logic of its own.

Just are there are people in Britain who will never accept things like gay marriage and mixed race relationships, there are others – in Brussels, in Lahore, in Baghdad and in Paris – who believe that all the ills of the world are attributable to Jews, Westerners and the "wrong" sort of Muslims.

Violent utopianism isn't new, of course; but nor is the attempt to explain it away as a response to Western policy. A good portion of the many column inches dedicated to explaining the 9/11 attacks relied upon an unwillingness to countenance the existence of movements that refused to embrace liberal democracy. The real spark of fascistic violence, so some progressives opined in hand-wringing op-eds, must be poverty and hardship. Similar excuse-making prevailed in explaining Nazism.

A soft racism underpins this fashionable rush to attribute blame for every expansionist or totalitarian movement to the West.

In the 1930s the Peace Pledge Union blamed the pathologies of Hitler, not on the mad doctrines of National Socialism, but on the "very serious provocation which many Jews have given by their avarice and arrogance when exploiting Germany's financial difficulties". More recently, Vladimir Putin was said by some to have invaded Ukraine in response to "Western provocation".

A soft racism underpins this fashionable rush to attribute blame for every expansionist or totalitarian movement to the West. Whereas at one time everything good in the world was said by Blimpish imperialists to lead back to us, the West is today seen by erstwhile anti-imperialists as the root of all evil.

Although it doesn't realise it, anti-imperialism has borrowed heavily from imperialism, and seems at times to exist primarily to take away the autonomy of people living outside the Western democracies. Whereas we rightly take seriously the ideas of our own domestic fascists, the far-right in the Muslim world are treated as small children acting up in response to poor Western parenting.

The far-right in the Muslim world are treated as small children acting up in response to poor Western parenting

Yet if, as some suggest, American imperialism really is the "root cause" of modern anti-Western terrorism; if the West really has brought terrorism on itself, there are several questions that urgently require an answer. First of all, where are the Cuban, the Argentinian and the Chilean suicide bombers? Where are the Guatemalans and the Brazilians intent on the random slaughter of "unpure" populations and the mass capture of sexual slaves? If fanatical religious ideology isn't the main driver of the spate of recent attacks, where are the masked Latinos rampaging through parks and shopping centres with Kalashnikovs?

As any good anti-imperialist ought to know, outside of South East Asia there is arguably no part of the world that has suffered more under the heel of American imperialism than its own supposed back yard. The Middle East certainly hasn't. Where, then, is the supposedly inevitable blow back?

Perhaps these chickens have failed to come home to roost because Islamist ideology is the driving force behind the recent upswing in jihadist violence after all. Could it be people sometimes believe in certain ideas and, as a consequence, perform certain actions. Or may be history tells us that, while most people just want to get on with their lives, a minority is sometimes willing to act with extreme violence in order to usher in utopia.