So, Barack Obama has commuted the sentence of whistleblower Chelsea Manning. Manning will be released in May. Now the US president must follow up that decision, before he leaves office this week, by giving a full pardon to Edward Snowden. Anything less will leave a stain on his presidency.

Snowden, who leaked classified information that revealed electronic surveillance abuses by America’s National Security Agency and Britain’s equivalent, GCHQ, is holed up in Russia. He is wanted in the US on three felony charges related to his disclosure of classified documents.

US government officials have suggested that a pardon for Snowden is highly unlikely, according to American current affairs website Politico. In part, this is because the information he handed over to journalists contained much more than the details about the NSA’s bulk electronic surveillance programmes. His flights from the US to Hong Kong, and then to Russia, have undermined calls for a pardon, Politico said, quoting unnamed officials.

Snowden is eager to return home to the US, but doesn’t believe that he will get a fair trial. He has said he will present a public interest defence if the government allows him a fair trial by jury.

Russia on Wednesday said it is willing to allow Snowden to remain in the country for “another couple of years”, according to foreign ministry spokeswoman Maria Zakharova. He has been in the country since June 2013.

Incoming US President Donald Trump could, however, complicate matters, especially given his rapprochement towards Russia and its president, Vladimir Putin. It’s not yet clear if or how friendlier relations between Russia and the US could affect Snowden’s position, but it must be giving the whistleblower sleepless nights.

The situation, frankly, is absurd. In blowing the whistle on the NSA and GCHQ, and invoking the wrath of the US government, Snowden lifted the lid on mass surveillance programmes that flew in the face of the civil rights that form a cornerstone of liberal democracy.

I wrote on TechCentral back in 2013 that the information leaked by Snowden showed a sophisticated plan by the British and American governments to implement an Orwellian system of mass surveillance that no one who holds the preservation of civil liberties dear could possibly support.

One difficulty for Obama in pardoning Snowden — assuming he has any desire to do so — is the message it might send to others with access to classified information. Intelligence agencies depend on secrecy, and rightfully so.

But nothing can justify the mass interception and theft of personal information revealed through Snowden’s leaks. It pointed to a violation of one of the basic tenets of liberal democracy. Snowden was absolutely right to blow the whistle.

As Amnesty International has put it, Snowden “stood up for our rights, prompting a global debate on mass surveillance that changed the world — yet he faces decades in prison for it”.

“His courage changed the world. He sparked a global debate, changing laws and helping to protect our privacy. Snowden is a human rights hero, yet he faces decades in prison under charges that treat him like a spy who sold secrets to enemies of the US.”