I am going through the introductory scenarios with a new group and so have been rereading the rulebook a lot and have a lot of questions (of things I previously believed to know!).
Anyway, according to 5.22
Germany and Italy may become allied whenever they wish, and automatically become allied if they go to war with the same Major Power.The way I read it is that they can ally even if not at war with the same MP (but automatically ally if they are).
However, per the scenario instructions Italy cannot declare war in the first turn. So is she prevented from allying Germany until the second turn, or can she do it (but not perform "Acts of War" as per 5.46)?
(Why would Italy ally with Germany if not to attack? Well, this way German units could enter Italy and prepare to strike France from the south as well, or the Italian SURFs could be moved to a German port to help with sea control, as soon as Italy can then declare on France or Britain.)