The Obama administration isn’t the only Western government facing questions about the use of NSA’s PRISM program to snoop on Internet content to expose potential terrorists.  David Cameron’s Foreign Secretary, William Hague, canceled a trip to Washington in order to address questions erupting in Parliament over British intelligence connections to PRISM and the potential to bypass UK proscriptions on surveillance:

William Hague, the Foreign Secretary, will face MPs’ questions today over fears that thousands of Britons could have been spied on by GCHQ through a covert link with the American security agencies.

Mr Hague, who has cancelled a trip to Washington to make a Commons statement, has insisted the law-abiding British public had “nothing to fear” from the work of the Cheltenham-based listing post.

He will come under pressure from MPs of all parties to spell out details of the co-operation between GCHQ and the previously-unknown Prism programme operated by the National Security Agency.

Sir Malcolm Rifkind, the chairman of the parliamentary Intelligence and Security Committee, said today that any request by GCHQ for access to British citizens’ emails or internet browsing habits would need proper legal authority, usually including the personal approval of a minister.

He told BBC Radio 4: “The law is actually quite clear: if the British intelligence agencies are seeking to know the content of emails by people living in the UK, then they actually have to get lawful authority. Normally that means ministerial authority.

“That applies equally whether they are going to do the intercept themselves or whether they are going to ask somebody else to do it on their behalf.”

Cameron himself insists that nothing illegal took place:

Cameron said: “Let us be clear. We cannot give a running commentary on the intelligence services. There are things that William Hague will be able to say and questions he will be able to answer. I am satisfied that the intelligence services, who do a fantastically important job to keep us safe, operate within the law and within a legal framework and they also operate within a proper framework of scrutiny by the intelligence and security committee.

“We do live in a dangerous world and live in a world of terror and terrorism. I do think it is right we have well-funded and well-organised intelligence services to keep us safe.”

Downing Street also said that GCHQ operated within the law. The prime minister’s spokesman said: “One of the things the foreign secretary said yesterday is: ‘If information arrives in the UK, it is governed by our laws.’

The prime minister believes, and very much agrees with the point that William Hague was making yesterday, which is that there is very strong ministerial oversight [of Britain’s intelligence agencies]. The prime minister thinks there is a very strong legal framework, there is very strong ministerial oversight, the foreign secretary noted the assessment by the commissioners, who are also part of the oversight process, with reference to the highest standards of integrity and legal compliance by GCHQ.”

Cameron reminded Britons that the war on terror requires ongoing vigilance, as the recent barbaric attack on a British soldier demonstrated.  He’s not the only one in the UK sounding that alarm, either.  David Petraeus will speak tonight in a veiled push-back against Barack Obama’s contention that the war on terror is over:

On a day when Britain’s chattering classes are obsessing about the latest revelations that Britain and America may share sensitive intelligence information (should we really be so alarmed about this?) General David Petraeus, one of America’s most renowned warriors and the former Director of the Central Intelligence Agency, will later today provide a far more sobering assessment of why we cannot afford to be complacent about the threat Islamist terrorism poses to our security.

Given the damage done to transatlantic intelligence-sharing by former Gitmo detainees, whose allegations of British involvement in torture resulted in sensitive American intelligence being splashed all over the front pages of the Left-wing press, I very much doubt Uncle Sam is giving us much intelligence material that is of interest in the first place.

But even if there is a link up between Britain’s GCHQ listening post in Cheltenham and its sister service, the NSA, we should be grateful for all the help we can get, if General Petraeus’s assessment is to be believed.

During a brief stopover in London today to receive a prestigious award for his distinguished service during the wars of the past decade, General Petraeus is giving a speech tonight in which he will issue this stark warning: “The Counter Insurgency Era is not over … because the Insurgency Era is not over”.

Well, it certainly doesn’t appear to be over on this side of the pond either, if we take lessons from Obama’s drone activities and the NSA.  But this does raise an interesting question about intelligence sharing and partnerships.  If the NSA developed the intelligence on British suspects and handed it over to the UK, would that really violate British law — or does British law only prohibit the Brits from developing that themselves?  That kind of sharing allows for all sorts of plausible-deniability opportunities that governments could use to get around restrictions.

Conversely, does the US have any laws prohibiting the government from using intel developed by our partners in the UK or elsewhere that would otherwise violate law in the US based on how it was collected?  Obviously the evidence might not be usable in court, but that kind of data might be used as probable cause to seek warrants here, depending on just how objectionable the source might be.  A sophisticated use of such sharing might produce what Alfred Hitchcock called “criss-cross” in Strangers on a Train (and hilariously parodied in the comedy Throw Momma From the Train).

That seems to be the worry from some Members of Parliament in the UK after discovering a possible link between British intelligence and PRISM. Perhaps the debate we’re about to have in the US might include that possibility, too.