The 31-year-old detainee is accused of fighting alongside al-Qaida in Afghanistan, and the hearing is seen as a test of the Bush administration's new system of military tribunals. Mr Hicks is a Muslim convert and one of some 385 prisoners held by the United States at Guantanamo.
He is the first terror suspect to face prosecution in revised military tribunals established after the US Supreme Court last year found the Pentagon's system for trying such detainees was unconstitutional.
He appeared clean-shaven yesterday, but his hair hung well below the shoulders of his khaki prison jumpsuit. He has told his lawyers he grew his hair to block the constant light in his cell.
Before his guilty plea early this morning, the former kangaroo skinner had asked for more lawyers, after the marine colonel judge barred two of his three lawyers from the tribunal. "I'm shocked because I just lost another lawyer," Mr Hicks told the court. The Bush administration's system of military tribunals has been widely condemned by legal and human rights organisations, and Mr Hicks has told his lawyers he does not expect a fair trial.
There had been speculation that Mr Hicks was considering a deal, presumably in exchange for a shortened sentence, after a confinement that is believed to have left him physically and mentally broken.
"He's been in the western world's most notorious prison for five years, the last year or so in pretty much isolation," David McLeod, an Australian lawyer, told National Public Radio. "It's been a pretty rough trot over the past five years. And if it was yourself, you would be thinking, I suspect, about how to get out of this place." Although Pentagon officials concede Mr Hicks may not have fired a shot at US forces in the 2001 war in Afghanistan, he could face a 20-year sentence. Under a diplomatic deal, Mr Hicks would serve that term in Australia.
Yesterday was his first appearance in public for three years, and his father and sister joined lawyers, representatives of rights organisations and journalists at the court. The latest hearings was authorised by Congress last year after the supreme court struck down earlier war crimes tribunals. Mr Hicks has been a casualty of that legal confusion which caused a nearly three-year hiatus . However, the tribunals have been widely condemned for allowing secret evidence obtained by torture.
In a nine-page charge sheet, the Pentagon says Mr Hicks began his journey to militancy in 1999 when he converted to Islam. It says he fought in Kosovo and Kashmir before receiving training from al-Qaida in Afghanistan in early 2001. He watched the September 11 2001 terror attacks from a friend's house in Pakistan, it says, "and expressed his approval".
But the charge sheet suggests Mr Hicks was only the most minor foot soldier for al-Qaida. He spent the first two weeks of the war in Afghanistan hundreds of miles from the fighting. He did eventually go to Kunduz, but the charge sheet says: "Hicks spent two hours on the frontline before it collapsed and he was forced to flee."
