provide most of the norms of behavior before, during and after a combat engagement. That's why initial training to thoroughly inculcate and embed the basics is so critical. Simply, people will do what they are trained to do -- and will not do things they are trained not to do. In combat, training and instinct take over.

To add other rules, the US has typically given theater or operation specific ROE (or UOF) training and issued ROE cheat sheets or pocket card. When we went to Little Rock, we got a two page UOF guideline direct from the JAG of the whole US of A Army + Division guidance + Arkansas Military District (MG Edwin Walker, Commanding ) guidance; when 11 years later, the Brigade I was in went to Detroit, we didn't get any UOF/ROE guidance other than verbal due to lack of time. No problems either way. In Korea, there were no ROE for all practical purposes, in Viet Nam, everyone got a pocket card. Other places, generally no rules or only a couple of quick verbals, i.e. Try to avoid killing civilians...

A letter sized sheet will be given general compliance, a pocket card gets a little better compliance but the bed rock is the training. Training based on best practice and what is legal is given and is generally adequate.

With respect to use of force (In the US) and the rules of engagement (in a combat area -- nominally overseas but not impossible in the US in some situations); the UOF would get throughly briefed and probably have a pocket card issued. Compliance would be, I believe pretty close to 100% -- with the caveat that the law enforcement like requirement to incapacitate (that's a really dumb law, BTW, says this Father of two Cops...) will cause difficulties from a training and thus a compliance standpoint -- shoot to kill in combat, shoot to wound in domestic situations, that's a hefty shift...

UOF compliance will be good because the troops realize that what they're doing is different and that fellow US citizens are involved. That restraint would lessen were the fellow citizens attempt to employ firearms. ROE compliance lessens a bit due to usually the non-US character of the opponents and due to the fact that others are generally shooting at us...

ROE compliance, OTOH is probably going to hover at ±99% in an Iraq * like situation, ±97% in Afghanistan and at about 90% in most more intense combat situations -- that is due partly to practical difficulties in compliance (i.e. opponents in civilian clothes firing from amidst a group of innocent civilians, firing errors, weapon malfunctions and human error mostly) and partly due to the fact that more intense combat lessens overall concern for human life and the inclination to be totally legal and very careful is lessened; the more intense, the more it is lessened.

* In early 2003, that compliance was probably around 90% or a little better due to more intense combat, less well trained troops and other factors. Compliance ramped up that and each succeeding year as the ROE got more restrictive, training improved and the intensity of conflict lessened.