But members of Blackwater are technically civillians, and not subject to the US Military Justice Code?
Yes, they are indeed civilians. There isn't anything technical about it. But, The Military Extraterritorial Jurisdiction Act specifically provides for the prosecution of civilian contractors working on behalf or in support of the US Military overseas, in US Federal Court.
Also, language inserted into the 2007 National Defense Authorization Act expanded those provisions and allowed for civilians working on behalf of the DOD to be prosecuted under the UCMJ.
I should point out that there was some (and continues to be) debate with respect to the ability to prosecute these private contractors who are not working for the DOD, but for either State or CIA. This has not been fully tested in court. If it holds up on appeal, is really anyone's guess.
Lastly, there is some additional gray area in this field for several different reasons. One reason includes certain Status of Forces Agreements (SOFA) that have been negotiated with these "host" countries. As an example, because of a provision is some DOD agreements prior to 2007, these Blackwater contractors (and others) were operating under a kind of blanket immunity, which really didn't allow for either US or Iraqi prosecution of these Blackwater contractors. With the negotiation of the latest SOFA agreement in Iraq, this immunity has been lifted.
that doesn’t matter anymore. BUSH passed a law where the DOJ had complete jurisdiction over personnel in war zones, all civilians under any capacity