Manning was charged with 22 counts, the most serious of which is “aiding the enemy”, for allegedly turning over a trove of classified US documents to WikiLeaks in one of the most serious intelligence breaches in US history.
The 24-year-old is accused of passing hundreds of thousands of military field reports from Iraq and Afghanistan and US diplomatic cables to WikiLeaks between November 2009 and May 2010, when he was serving in Iraq.
The leak of the military documents shed light on civilian deaths, while the diplomatic cables sparked a firestorm by disclosing the private remarks of heads of state and candid observations by senior US officials.
The US government slammed the disclosure of the documents by WikiLeaks, saying it threatened national security and the lives of foreigners working with the military and US embassies.
WikiLeaks supporters view the site as a whistleblower that exposed US wrongdoing and see Manning as a political prisoner.