Practice Relating to Rule 101. The Principle of Legality
Argentina’s Law of War Manual (1969) provides: “Tribunals will only apply legal provisions existing previously to the offence.” It adds that the “legal provisions decreed by the Occupying Power … cannot have a retroactive effect”.
Argentina’s Law of War Manual (1989) states that the prisoner shall be informed of the offence for which he or she is charged, an offence “which shall constitute a criminal act at the time it was committed”.
The manual further states that criminal provisions “cannot have a retroactive effect” and that the alleged offence against the accused “must constitute a criminal act at the moment it was committed”.
The same provision applies in non-international armed conflicts.
Argentina’s Law on the Implementation of the 1998 ICC Statute (2006) states: “No provision establishing criminal offences under the Rome Statute [1998 ICC Statute] or this law shall be applied in violation of the principle of legality”.