Règle correspondante
Practice Relating to Rule 145. Reprisals
Section B. Reasonable notice and measure of last resort
Australia’s Defence Force Manual (1994) states: “Some nations may not comply with LOAC in the conduct of armed conflict. Where this occurs, and all methods of persuasion and diplomatic pressure have failed, reprisals may be justified but only against military objectives.” It adds: “In any case, reprisals must … only be resorted to after lesser forms of redress have been tried.” 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 1310; see also Law of Armed Conflict, Commanders’ Guide, Australian Defence Force Publication, Operations Series, ADFP 37 Supplement 1 – Interim Edition, 7 March 1994, §§ 1210 and 1211.
Australia’s LOAC Manual (2006) states:
In order to qualify as a legitimate reprisal, an act must comply with the following conditions when employed … [including] … The victim of a violation must first exhaust other reasonable means of securing compliance before reprisals can be justified. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, § 13.18.
The LOAC Manual (2006) replaces both the Defence Force Manual (1994) and the Commanders’ Guide (1994).
The Report on the Practice of Australia states: “Australia’s opinio juris is, with certain exceptions, supportive of a prohibition against belligerent reprisals.” It adds, however: “Australian opinio juris does not consider that exceptions to the prohibition against reprisals, where these represent measures of last resort, will place it in breach of its customary obligations.” 
Report on the Practice of Australia, 1997, Chapter 2.9.