In a statement posted on the WikiLeaks website, he said: "When communicating with the press is 'aiding the enemy' it is the 'general knowledge among the people' itself which has become criminal.
"Just as Bradley Manning is condemned, so too is that spirit of liberty in which America was founded.
"In the end it is not Bradley Manning who is on trial. His trial ended long ago. The defendant now, and for the next 12 weeks, is the United States.
"A runaway military, whose misdeeds have been laid bare, and a secretive government at war with the public. They sit in the docks. We are called to serve as jurists. We must not turn away."
More top news
The prime minister said "tough new rules" will be introduced to tackle the behaviour of executives who put their workers' pensions at risk.
The musician, whose career spanned six decades and included 18 years with The Kinks, died on Saturday after a fall.
A group of soldiers has broken an Antarctica record by becoming the first all-female team to cross the continent using only muscle power.