Quote Originally Posted by Tukhachevskii View Post
I think a large part of the problem is that the reconnaisance function/role tends to blur into the advance guard function/role which then confuses force design or, as in the case of Iraq, S/BCT recon elements are often used as a de-facto third manouvre element...so who's doing recon?
The "third manoeuvre element" thing is a consequence of designing cavalry as a de-facto brigade instead of as many small autonomous units (Coy).
That's one of the reasons why the ACR concept is strange.

German WW2 doctrine gave the fast division's recce detachment some combat tasks, too. They were only capable of small combat missions, though.
Standard doctrine was to send small teams of armoured cars ahead and to increase their density in areas of interest. Those armoured cars would avoid combat if possible.
The recce detachment was reinforced with a fast-moving infantry Bn (initially motorcycle troops), though. They were able to punch through screening lines or to grab an important hill or bridge if necessary. Organic artillery and AT guns helped them (they did later go for long 75mm cannons on lightly armoured AFV for both direct fire support and AT support).

That wasn't enough to be misunderstood as an additional manoeuvre element. It was enough for small combat missions (especially against unprepared opposition) and was often mis-used as emergency reserves in times of crisis (this happened to everybody in uniform, though - engineers and recce troops were merely the first to be called upon).