This chapter takes a close look into the United States’ 9/11 military commission trials in the light of the ‘Decaux Principles’ of 2006 concerning the legal framework for the proper administration of justice by military tribunals. The first section presents the legal framework of the military commissions, and the second section discusses the procedure of the 9/11 trial and its actual functioning. One of the lessons that can be learnt from this more than 18 year long Guantanamo Bay experiment is that justice and military operations are two distinct matters: the two involve different sets of goals, actors, and modes of operation. Attempting to hybridize them is therefore not desirable. Opting for ordinary civilian courts as the prevailing jurisdiction responsible for the prosecution of persons accused of terrorism is, in most cases, the better option – maybe only option – for handling justice.