While never mentioning either Snowden or the Guardian by name in his speech, Parker defended the need for widespread and secret electronic surveillance. He described MI5 as an efficient and effective organization "well placed to tackle the bulk of the threats we face, because of the support we receive from our colleagues in GCHQ, SIS and the police and, most of all, because of the commitment of the men and women who make up MI5."
It is a description in stark contrast to that painted by Adam Curtis in the BBC Blogs. Titled simply Bugger, Curtis provides a potted history of an organization originally founded on a fictional threat and developing into "the story of weirdos who have created a completely mad version of the world that they then impose on the rest of us."
Parker's version of the world is one in which the UK is under constant terrorist threat, but where "Lethal terrorist attacks in the UK remain rare. MI5 and partners have a long track record of detecting and preventing most attempts."
Key to that detection and prevention is the intelligence provided by GCHQ through electronic surveillance, but he stressed that it was limited and necessary. "This is not East Germany, or North Korea," he said. "There seems to be a vague notion that we monitor everyone and all their communications, browsing at will through people's private lives for anything that looks interesting. That is, of course, utter nonsense," he said.
Nevertheless, the information provided by GCHQ "is vital to the safety of this country and its citizens." Referring to the current debate, he added, "It causes enormous damage to make public the reach and limits of GCHQ techniques. Such information hands the advantage to the terrorists. It is the gift they need to evade us and strike at will. Unfashionable as it might seem, that is why we must keep secrets secret, and why not doing so causes such harm."
His speech has been endorsed by prime minister Cameron ("it was an excellent speech"), but widely criticized elsewhere. The Guardian's editor Alan Rusbridger, speaking to BBC Radio 4, challenged the notion that the leaks would aid terrorists: "I don't think some of this will come as a great surprise to terrorists."
Eric King, head of research at Privacy International, commented on the reference to East Germany. "Andrew Parker is right: the UK isn't East Germany. While the Stasi had files on one in three East Germans, the communications of almost everybody in the UK are being intercepted and stored as part of GCHQ's Tempora programme. Our security agencies' continued insistence that they are not prying, while every week new mass surveillance programmes are being revealed, is offensive to the public's intelligence."
In the US, Ron Wyden pointed to the difference between secret operations and secret law. "I take a back seat to no member of Congress when it comes to protecting the secrecy of what's called sources and methods," he said. "Secret operations have to be sacrosanct. But that's not what we're talking about, we're talking about the policies that undergird this surveillance debate."