The US still has military spending that is higher in real, inflation-adjusted terms than it was during the peak of the Reagan cold war build-up, the Vietnam war and the Korean war. We seem to be in a state of permanent warfare, and – we have recently learned – massive government spying and surveillance of our own citizens. This is despite an ever-receding threat to the actual physical security of Americans. Only 19 people have been killed by acts of terrorism in the US since 11 September 2001, and none or almost none of these was connected to foreign terrorists. Also, there are no "enemy states" that pose a significant military threat to the US – if any governments can be called "enemy states" at all.

One of the reasons for this disconnect is that most of the mass media provide a grossly distorted view of US foreign policy. It presents an American foreign policy that is far more benign and justifiable than the reality of empire that most of the world knows. In a well-researched and thoroughly documented article published by the North American Congress on Latin America (NACLA), Keane Bhatt provides an excellent case study of how this happens.

Bhatt focuses on a popular and interesting National Public Radio (NPR) show, "This American Life" and, most importantly, an episode that won the Peabody Award. The Peabody Award, for distinguished achievement in electronic journalism, is a prestigious prize. So, it makes the example even more relevant.

The episode was about the 1982 massacre in Guatemala. The story gives compelling eyewitness accounts of a horrendous slaughter of almost the entire village of Dos Erres, more than 200 people. The women and girls are raped and then killed; the men are shot or bludgeoned with sledgehammers; and many, including children, are dumped into a dry well – some while still alive – that would become their mass grave. The broadcast walks the listener through a heroic investigation of the crime – the first ever to win punishment for such murders. And finally, it provides a moving account of one survivor who was three years old at the time. Three decades later, while living in Massachusetts, he discovers his roots and his biological father as a result of the investigation. The father lost his wife and his eight other children, but he survived because he happened to be out of town on the day of the massacre.

The story makes it clear that this bloodbath was one of many:

This happened in over 600 villages, tens of thousands of people. A truth commission found that the number of Guatemalans killed or disappeared by their own government was over 180,000.

But there is one striking omission: the US role in what the UN Truth Commission in 1999 later determined to be genocide. The UN specifically noted Washington's role and President Clinton publicly apologized for it – the first and, to my knowledge, the only apology from an American president for US involvement in genocide. The US role in providing arms, training, ammunition, diplomatic cover, political and other support to the mass murderers is well-documented, and has gotten some more documentation and attention as a result of the recent trial of former military dictator General Efraín Ríos Montt, who ruled from 1982-83. (As Bhatt notes, the program states the US embassy had heard reports of massacres during this time but "dismissed" them; but this is very misleading at best – there are cables showing that the embassy clearly knew what was going on.)

In fact, one of the soldiers who participated in the Dos Erres massacre, Pedro Pimentel, who later was sentenced to 6,060 years in prison, was airlifted the day after the mass murder to the School of the Americas, the US military facility known for training some of the region's worst dictators and human rights violators.

It is astonishing that one of the worst genocides of the post-second world war era was allowed to reach its peak, just a couple of hours of flying time from the US mainland, with almost no media reporting on it. Here you can find investigative journalist Allan Nairn interviewing a Guatemalan soldier in 1982, who describes how he and his comrades murdered whole villages, as in Dos Erres. And yet, the major media ignored it, allowing Ronald Reagan to promote Ríos Montt as "a man of great personal integrity and commitment". So the omissions of "This American Life" are ironic in this historical context, as well.

It is clear from the piece that Ira Glass, the show's host, was well aware of the US role in the Guatemalan genocide. In the 1980s, it appears, he traveled to Central America and was active against the US-funded wars and war crimes in the region. In an email correspondence with Bhatt, he acknowledges that "maybe we made the wrong call" in leaving out the US role.

That is an understatement, but a vitally important one. For a program broadcast in English throughout the US, this is arguably the most important thing Americans need to know about the genocide.

I'm not faulting Glass. He may well have guessed that if he had made a point out of the US role, and maybe questioned some of the US officials who were responsible for it, the story would have run into trouble at NPR. It certainly wouldn't have gotten a Peabody Award.

That's what makes this such a compelling illustration of how censorship and self-censorship operate in the US media. It demonstrates, at the micro-level, something I have seen countless times in the past 15 years of talking with journalists about these issues. They have a good idea what the boundaries are and how much truth they can get away with. I have met many good journalists who try to cross these boundaries, and some succeed – but they often don't last long.

Scott Wilson, who was a foreign editor at the Washington Post and covered Venezuela during the short-lived coup against the democratically elected government of Venezuela in 2002, stated in an interview that "there was US involvement" in the coup. Yet, this important fact never appeared anywhere in the Post, nor was it reported by any major US media outlets, despite considerable evidence from US government documents that it was true. Again, this is arguably the most important part of the story for a US audience – especially since it played a major role in poisoning relations between Washington and Caracas over the past decade and probably had a significant impact on relations with the whole continent of South America. But, as in the Dos Erres story, the US role in the crime is unmentionable.

The same is true for the US role in the coup that destroyed Honduran democracy in 2009. The Obama administration's considerable efforts to support and legitimize the coup government were not considered to be newsworthy by US journalists. (A program on Honduras was Bhatt's other shot at "This American Life", where it left the US-supported coup out of a picture in which it should have had a prominent place.) But this, too, is off limits for US media.

What would US foreign, military and so-called "national security" policy look like if the media reported the most important facts about it? There would be a lot fewer corpses abroad and returning home. And we wouldn't be cutting "meals on wheels" or other nutrition programs for the poor or elderly in order to sustain the world's most fantastically bloated military budget.