Ah, but now you bring up the sea aspect to all of this! When was the MAS created? Would the Italian Navy be capable of a strike like this? Would it risk it? Trieste and any ports the Austrian Navy is harbored would be the primary targets. Do you think diplomacy and negotiation for Trieste and the Trentino would still be an option, given the Austrians' tenuous grip on its own empire?
Well OTL the MAS aka
Motoscafo armato silurante (Torpedo armed motorboat) was created during the first world war to use against submarine and against surface vessel in infiltratation operation and hit and run tattic; depending on the configuration. It was developed because was very usefull in the shallow water of the Adriatic and in WWII with better and more advanced boat the range and the scope of the operation increased; even including a scuba incursion.
So the reason to develop the unit and the gear still exist ITTL, with also a lot of enphasis on the port of Vlore and Dures in Albania, as with A-H in control of the territory they can menace italian south and even try some invasion/at least heavy incursion.
Italy will surely try to negotiate first, the problem is how the previous negotiation had developed and what's the general relationships between the two nation; as said earlier, it's difficult to believe that Italy had remained neutral while A-H had gone in to inglobe the balkans without requesting a compensation...and if an agreement had been reached, by the map seem that Wien and broken it and this mean that fromt the italian side any attempt at negotiate with A-H will short, on point and uncompromising; the continuing ethnic strife in the 30's and during the war, the conflict itself (sure A-H has never been directly menaced, but internal terrorism, air attack and the general economic and social toll of the war will have greatly weakened) and even Germany needing some breathing time mean that any goverment in Rome will think that this is the right moment to put some request towards Wien as the first great war demonstrated that being patient mean just giving them the time to rebuild and stabilize without getting anything.
https://en.wikipedia.org/wiki/Francesco_Caracciolo-class_battleship will happen ITTL as money is not that tight and there is the need to guard against A-H and France, probably heavily modernizated in the 30's like the OTL Conte di Cavour and Andrea Doria
https://trucioli.it/2012/11/22/la-portaerei-bonfiglietti-del-1929/ with a little more money and without the need to keep all the various services at each other throat (more than the usual naturally), Regia Marina can have an aircraft carrier
Right. This assumes that a neutral Italy draws the right the lessons from the war going on around it. And has the industry and funds to produce the materials capable of making such doctrine possible. Douhet seems to have been a firm advocate of air power and strategic bombing, forming his theories based on what he experienced during the Italo-Turkish War. His theories on strategic bombing were certainly put to the test in our timeline, so I wonder if those lessons would still be looked at in TL-191. Billy Mitchell seems to have been a fan, for example.
There was one major aspect of his theories though that seemed to be a major problem - that air power alone could win a war if enough bombs were dropped on the right targets, basically breaking the people's will to fight. Wasn't exactly the case unfortunately. I believe you'd still need ground forces to apply pressure on the ground, combined arms warfare. The Isonzo is a massive challenge to overcome. I agree that air power and air coverage over this front would be to the benefit of the Italians, and paratroopers can be a massive asset if deployed correctly. They'd still need to coordinate with the army I feel, however.
Well, without the war and without Benny and co. in charge Italy will have more funds (even because no invasion of Abyssinia and massive waste of resources in Spain) and a more sane industrial politics aka the freebies will be much more limited and the goverment will have less problem in buy foreign vehicles if the locals can't deliver or try to milk too much from the contracts...i don't say that all this will not happen, just it will be limited to the normal level of a democracy.
So, even if it will be difficult and costly, and frankly i doubt that Italy will be capable to have everything she need for that...it will be better than OTL; regarding the doctrine, i think that (ironically) Trentino and Istria will be spared by heavy bombardment and here the limit will be at tattic and air support level, there will be instead a concentrated effort in OTL Austria and Croatia.
Sure there will be the need to troops and coordination, plus the second great war will clearly show the limit of Dohuet theory, still Italy will need to roll the dice she had and even if i doubt that the italian military enstablishment will ever reach OTL German level performance, i believe that they will reach a sufficient level of professionality to attempt this type of offensive.
All this mean that the italian armed forces will have in general a better equipment than OTL and i expect a somewhat better officer corps (worse is difficult) as the yes men will not be so encouraged and political appointment more limited, plus no binary division reform