> One of their interests is telling the truth to their local military and politicians - getting caught in a lie to their side is the worst that could happen to them.

It's definitely not the worst that can happen. Happens fairly often - google: CIA lying to congress. Getting audited is the worst that thing that happens to the CIA. ie The U.S. Government Accountability Office (GAO) last actively audited the Central Intelligence Agency (CIA) in the early 1960s, specifically discontinuing such work around 1962.