In The War You Don't See Pilger looks at the public relations exercises undertaken to make sure that the public never get to know what really goes on in war.

Journalists have become complicit in this process.

The film opens with footage of an appalling slaughter by US forces in Iraq, where people were gunned down, but this then switches to World War I with sights of some of the grisly scenes from that conflict.

Pilger recalls the conversation between the editor of the Manchester Guardian of the time CP Scott and prime minister Lloyd George, who declared that "if the people really knew the truth about the war it would be stopped tomorrow but they don't know and can't know."

This mantra has pretty much guided every conflict involving the British government in the intervening years since 1918.

The subtlety of the process required to make the unacceptable acceptable to the public has grown over the years with the increasing power of the public relations industry over that of independent journalism.

Too many have all too easily traded the role of inquisitor for that of sipher of official truths.

One of the best examples of how the media has sold its independence short is the practice known as embedding. Some 700 reporters were embedded with US and British forces when they attacked Iraq.

This results, as the former BBC correspondent Rageh Omaar admits, in the type of collusion that saw the fall of Basra reported 17 times before it actually happened.

It also, as lawyer Phil Shiner points out, made the reporting of human rights abuses committed by US and British forces unlikely in the mainstream media.

The contrast comes with the few independent journalists who went into Iraq and Afghanistan, bringing out appalling stories of brutality and murder.

The mainstream networks were not interested, not even by way of balance to the one-sided nature of their own coverage.

Pilger pushes the question of balance.

Why are the accounts so one-sided in favour of the war-making establishment? Where are the dissident voices?

The balance issue is most clearly exposed by coverage of Israel.

Pilger grills the BBC particularly as to why Israel's "chief propagandist" Mark Ragev got a free run at the top of a news report with no balancing viewpoints.

This means that stories like the shooting by Israeli soldiers of those on the aid convoy to Gaza earlier this year are told almost entirely from an Israeli perspective.

Tel Aviv's approach to public relations is aggressive and blunt. Its representatives make life so difficult for any journalist trying in whatever way to show the other side that they either end up presenting the official Israeli line or steering clear of the subject altogether.

The Glasgow Media Group's Greg Philo tells how a senior producer had confided to him that they "wait in fear for the phone call from the Israelis" after doing a piece on that country.

The work of WikiLeaks and independent journalists becomes all the more important in this context.

The unpalatable truth that emerges from the film is that the public have been led into disasterous wars in Iraq and Afghanistan without ever being given the truth of the situations concerned.

Truths like the growing number of civilian casualties.

So while 10 per cent of victims in the first world war were civilians, this figure had risen to 90 per cent by the Iraqi conflict.

The unanimity of the mainstream media in shutting out almost everything except the official version of events is truly frightening.

It can only be hoped that the revelations of Wikileaks and this film help spark a process that leads to more of the truth getting out there as to what really is going on and in whose vested interests the various wars are being pursued.

There is a wider point for journalists on the need to question official truths.

Too many journalists are all too willing to follow officially set guidelines on whatever the leading crisis of the day is set to be, whether it be war, financial crisis or climate change.

It is vital for journalism and democracy that independent voices can be heard and that those who govern us are made accountable for what they do.

The War You Don't See is on ITV at 10.35pm on December 14.