WikiLeaks founder Julian Assange's protracted effort to fight extradition to Sweden suffered a body blow this week. Britain's supreme court upheld the arrest warrant, issued in December 2010.

After the court announced its split 5-2 decision, the justices surprised many legal observers by granting Assange's lawyers an opportunity to challenge their decision – the first such reconsideration since the high-profile British extradition case from more than a decade ago against former Chilean dictator Augusto Pinochet. The decision came almost two years to the day after Private Bradley Manning was arrested in Iraq for allegedly leaking hundreds of thousands of classified US government documents to WikiLeaks.

The cases remind us that all too often whistleblowers suffer, while war criminals walk.

Assange has not been charged with any crime, yet he has been under house arrest in England for close to two years, ever since a European arrest warrant was issued by Sweden (importantly, by a prosecutor, not by a judge). Hoping to question Assange, the prosecutor issued the warrant for suspicion of rape, unlawful coercion and sexual molestation. Assange offered to meet the Swedish authorities in their embassy in London, or in Scotland Yard, but was refused.

Assange and his supporters allege that the warrant is part of an attempt by the US government to imprison him, or even execute him, and to shut down WikiLeaks. In April 2010, WikiLeaks released a US military video under the title Collateral Murder, with graphic images showing an Apache helicopter unit killing at least 12 Iraqi civilians, including a Reuters cameraman and his driver. In July 2010, WikiLeaks released the Afghan war diary, tens of thousands of secret US military communications that laid out the official record of the violent occupation of Afghanistan, the scale of civilian deaths and likely war crimes. The Swedish arrest warrant followed just weeks later.

So many public figures have called for Assange's assassination that a website was created to catalogue the threats. Former Arkansas governor, presidential candidate and Fox News commentator Mike Huckabee said that, for Assange, "anything less than execution is too kind a penalty". Prominent conservative Bill Kristol asked:

"Why can't we use our various assets to harass, snatch or neutralize Julian Assange and his collaborators, wherever they are?"

Death threats from rightwing ideologues are one thing. The main concern with an extradition to Sweden is that Assange will then be extradited to the United States. In another prominent document released by WikiLeaks, called the Global Intelligence Files, a portion of up to 5m emails were released from a private, global intelligence firm called Stratfor, based in Austin, Texas. The firm's vice president for intelligence, Fred Burton, wrote in a 26 January 2011 email:

"Not for Pub – We have a sealed indictment on Assange. Pls protect."

If an indictment has been issued in secret, then Assange could find himself in US custody shortly after landing in Sweden. He could be charged with espionage (the Obama administration has already invoked the law more than all previous US administrations combined), and could be imprisoned for life or executed.

The United Kingdom carefully considers extradition requests, as famously demonstrated when crusading Spanish judge Baltasar Garzon hoped to prosecute former Chilean dictator Pinochet for torture committed under his rule from 1973 to 1990. Based on Garzon's indictment, Pinochet was arrested in 1998 while travelling in London. After 16 months of hearings, the British courts finally decided that Pinochet could be extradited to Spain. The British government intervened, overruling the court, and allowed him to return to Chile.

Garzon is known for taking on global human rights cases under the doctrine of universal jurisdiction, indicting Osama bin Laden for the 9/11 attacks and probing the abuse of US prisoners at Guantánamo Bay. When he began investigating abuses under the fascist government of general Francisco Franco, who ruled Spain for 40 years, Garzon became the target of the right in Spain and was disbarred in early 2012, effectively ending his legal career.

Judge Garzon and Julian Assange have taken on entrenched power, whether government, military or corporate. Bradley Manning stands accused of the same. In differing degrees, their lives have forever changed; their careers, their freedoms and their reputations were threatened or destroyed.

This week, Hillary Clinton will be the first US official to visit Sweden in years. Why? What role is the US government playing in Assange's case? This week's developments bear crucially on the public's right to know, and why whistleblowers must be protected.

• Denis Moynihan contributed research to this column

© Amy Goodman 2012; distributed by King Features Syndicate