It is fine and fair that the Allied powers can DoW Italy.
But it must come with a cost. They're the democrats, they're not meant to go around declaring war nilly-willy.
I like the World in Flames approach there - which is easily applicable in Warplan. If UK / France declare war to Italy, or any neutral in general, it comes with a hit on USA % of production, and a delay in their war entry. (Just think that Pearl Harbour still happens, but the USA focus more on Japan, or have a belargued intervention in Europe.) Each DoW delays the USA entry. Plain and simple. Once USA kicked in ... well ... they can do as they please.
That consists in an effective choice, and not a 'no brainer' to instantly declare war to poor Italy and overwhelm them whilst they're repairing troops and so forth.
Alternatively other games simply give Italy a neat production boost and free units, IF they're declared war upon (mirroring deeper motivation of the Italians, as they're not fighting the Duce's imperialistic war, but they're actually fighting a war they've been pulled into by enemy aggression.)
Nonetheless, that the Allies can declare war to Italy, for free (or just bump up to 100 their status), should not be allowed.
EDIT / Clarification: The AI can be set to DOW Italy when Italy is at 100% without penalty. It will easen the AI computing and math.
A player on the other hand, with their full brain capability to plan, arrange and organize, must incur in a penalty if the UK and France declare war to Italy.
From the programming end, it should be quite simple to script something based on "Is Allied_Player AI? Yes, do X. No, do Y". A big IF function pratically!
< Message edited by Cohen_slith -- 10/25/2019 8:30:33 PM >