The Committee on Women in NATO Forces used to publish an annual report on gender integration in each member nation's military. The most recent I could find with a quick Google search (caffeine hasn't taken hold yet) was 2004's:
http://www.nato.int/ims/2004/win/03-index.htm
It looks like that working group may have been replaced by the NATO Committee on Gender Perspectives:
http://www.nato.int/cps/en/natolive/topics_50327.htm
Yes, I know the thread's specific to American forces, but looking at some of our NATO partners might provide some insight into how such integration would proceed here if sufficient political pressure mandated it.
- C.