Dear Alan,

There is plenty of time – and there are abundant venues – to debate relevant questions about Mr Snowden's historical role, his legal fate, the morality of his actions, and the meaning of the information he has chosen to disclose.

But your appearance before the Commons today strikes me as something quite different in purpose and dangerously pernicious: an attempt by the highest UK authorities to shift the issue from government policies and excessive government secrecy in the United States and Great Britain to the conduct of the press – which has been quite admirable and responsible in the case of the Guardian, particularly, and the way it has handled information initially provided by Mr Snowden.

Indeed, generally speaking, the record of journalists, in Britain and the United States in handling genuine national security information since World War II, without causing harm to our democracies or giving up genuine secrets to real enemies, is far more responsible than the over-classification, disingenuousness, and (sometimes) outright lying by a series of governments, prime ministers and presidents when it comes to information that rightly ought to be known and debated in a free society. Especially in recent years.

You are being called to testify at a moment when governments in Washington and London seem intent on erecting the most serious (and self-serving) barriers against legitimate news reporting – especially of excessive government secrecy – we have seen in decades.

The stories published by The Guardian, the Washington Post and the New York Times based on Mr Snowden's information to date hardly seem to represent reckless disclosure of specific national security secrets of value to terrorists or enemy governments or in such a manner as to make possible the identification of undercover agents or operatives whose lives or livelihoods would be endangered by such disclosure. Such information has been carefully redacted by the Guardian and other publications and withheld from stories based on information from Mr Snowden. Certainly terrorists are already aware that they are under extensive surveillance, and did not need Mr Snowden or the Guardian to tell them that.

Rather, the stories published by the Guardian – like those in the Washington Post and the New York Times – describe the scale and scope of electronic information-gathering our governments have been engaged in – most of it hardly surprising in the aggregate, given the state of today's technology, and a good deal of it previously known and reported and indeed often discussed "on background" with reporters by high government officials from the White House to Downing Street confident that their identities will not be disclosed.

Moreover, the Guardian—like the Times and the Post in the US – has gone to great lengths to consult with Downing Street, the White House and intelligence agencies before publishing certain information, giving time for concerns to be raised, discussed sensibly, and considered.

What is new and most significant about the information originating with Mr Snowden and some of its specificity is how government surveillance has been conducted by intelligence agencies without the proper oversight – especially in the United States – by the legislative and judicial branches of government charged with such oversight, especially as the capabilities of information-gathering have become so pervasive and enveloping and with the potential to undermine the rights of all citizens if not carefully supervised. The "co-operation" of internet and telecommunications companies in some of these activities ought to be of particular concern to legislative bodies like the Commons and the US Congress.

As we have learned following the recent disclosures initiated by Mr Snowden, intelligence agencies – especially the NSA in the United States – have assiduously tried to avoid and get around such oversight, been deliberately unforthcoming and oftentimes disingenuous with even the highest government authorities that are supposed to supervise their activities and prevent abuse.

That is the subject of the rightful and necessary public debate that is now taking place in the US, the UK and elsewhere.

Rather than hauling in journalists for questioning and trying to intimidate them, the Commons would do well to encourage and join that debate over how the vast electronic intelligence-gathering capabilities of the modern security-state can be employed in a manner that gives up little or nothing to real terrorists and real enemies and skilfully uses all our technological capabilities to protect us, while at the same time taking every possible measure to insure that these capabilities are not abused in a way that would abrogate the rights and privacy of law-abiding citizens.

There have always been tensions between such objectives in our democracies, especially in regard to the role of the press. But as we learned in the United States during our experience with the Pentagon Papers and Watergate, it is essential that no prior governmental restraints or intimidation be imposed on a truly free press; otherwise, in such darkness, we encourage the risk of our democracies falling prey to despotism and demagoguery and even criminality by our elected leaders and government officials.

With warmest regards and admiration,

Carl Bernstein