In my solo learning game a following question arose:
The Naval Outflank and Commando Raid Allies' events use the word Invasion in their text, and I wonder if they cause a German Invasion Reaction like big Major Offensive landings. It appears to be a very bad tradeoff to send one unit of Commandos just to cause quick arrival of OKW units. This looks like a German overreaction for diversion landings.
I decided that these small invasions do not cause reactions, but now it's time to confirm or denounce it - the Germans already had strength in numbers at this moment (both sides were without loses).
This is correct, only "Major Invasions" cause the reaction.
[13.6.9] German Mainland Invasion Reaction: When the Allied player invades (13.6) the Italian mainland for the first or second time (i.e., any map but Sicilia), the German player receives the reinforce- ments indicated in the 1st or 2nd Mainland Invasion Box of his Strategic Map Display card if they are still available.
Allied units and Landings markers may enter the map from the Allied Reserves Box to LZ hexes. Invasions happen during Major Offensives if the Event card used for the Offensive has a ship icon (5.2.5).