Lord Chief Justice Lord Burnett based the decision after the U.S. government sent assurances that Assange would not be subject to "special administrative measures" while in custody. U.S. officials also promised that Assange would receive "appropriate clinical and psychological treatment" and that he would not be held in a maximum-security prison. If convicted, officials said they would allow Assange to file a request to serve his prison sentence in an Australian jail.
Burnett noted that those assurances were not in place when the previous decision to deny Assange's extradition was made.
"That risk is in our judgment excluded by the assurances which are offered. It follows that we are satisfied that, if the assurances had been before the judge, she would have answered the relevant question differently," Burnett said.
Assange faces 18 charges under the Espionage Act for his role in publishing classified military and diplomatic cables. If convicted on all counts, the 50-year-old faces up to 175 years behind bars.
Assange's legal team said they plan to appeal the ruling.