The hearing is expected to last five days. Manning stands accused of multiple charges of computer fraud, theft of public property or records, transmitting defense information (thus violating the Espionage Act) and causing the stolen information to be published online.
He is also facing one charge of aiding the enemy - a charge that can end up in a capital punishment. But, according to Wired, the government has previously stated that it will not be asking for that. If Manning gets convicted of all the charges laid against him, though, he could end up in prison for life.
"The primary purpose of the Article 32 hearing is to evaluate the relative strengths and weaknesses of the governmentís case as well as to provide the defense with an opportunity to obtain pretrial discovery," David Coombs, Manning's lead counsel, explains in a blog post. "The defense is entitled to call witnesses during the hearing and to also cross examine the governmentís witnesses. Each witness who testifies is placed under oath; their testimony can therefore be used during the trial for impeachment purposes or as prior testimony should the witness become unavailable."
Manning was arrested in May 2010, after having boasted about providing WikiLeaks with combat videos (including that of the helicopter attack made public by the site in April) and a massive amount of classified State Department records.
He has since been confined to a cell at the Marine Corps Base in Quantico, Virginia, and later moved to Fort Leavenworth, Kansas.