Military justice has to be portable because armies deploy. Field operations in unfamiliar environments generate their fair share of military justice controversies. Some of these are a function of the imposition of special rules intended to prevent friction with the local populace. Other deployment-related prohibitions may reflect requirements of the law of war, including the Geneva Conventions. ‘Military justice in the field’ explains that battlefield crimes have proven to be both difficult and controversial to prosecute. At times there have been questions about which rules of engagement governed. Bringing cases to court also requires a series of obstacles to be overcome. Where should trials be conducted when crimes are committed on deployment?