Re: Collective Punishment of Civilian Population - Ardeatine Caves Massacre.
Interesting post. Certainly I'm not qualified to answer your questions, especially in the context of the "legislative intent" behind the law (I think what I'm doing is "responding," and off the cuff, at that). But my layman's reading of the word "proportionate" suggests a ratio of 1:1, not 10:1, would have been "appropriate." I believe that the Germans made wide use of the 10:1 ratio, in the Balkans and elsewhere. Even with the racial theories, did they really think a German was worth 10 of anybody else? What exactly was their rationale behind the ratio? (yeah, I know they want to raise civilian fear, and inhibit partisans with the "cost," but such for purposes, I would think 1:1 would work just about as well (or, on the theory trained soldiers cost a state "more," even a 2:1 ratio would seem "ample.") Those ratios might arguably be proportionate (1. Forming a relationship with other parts or quantities; being in proportion. 2. Properly related in size, degree, or other measurable characteristics; corresponding: Punishment ought to be proportional to the crime. 3. Mathematics Having the same or a constant ratio.)
Regarding your second question, the idea of killing only criminals or those already condemned to die seems to undermine what theory exists behind the "proportional" response. Though one might observe a certain irony in the selection of criminals in return for killing servants of the Nazi state.... In any case, partisans & retaliation isn't one of my strong points. I suspect the obvious: Italy's long-term alliance with Germany, the nominal alliance with the RSI all were factors. Possibly, they didn't want to stir up "too much" civilian anger at Germany due to the proximity of Allied Forces, though if that was the motivation, it seemed a concern addressed a tad unevenly, as I (dimly) recall reading what was going on in Rome about this time. Don't know if I'm addressing the question quite as you meant it, and as for the rest of it, I won't venture a response at the moment. Just be interesting to see what anyone else might say....
"...we have met the enemy and he is us." -- Pogo (Walt Kelly)