I think the Po Valley will be massively different than OTL
I can’t answer for the Italians, but with some Allied troops amongst them I would hope they’ll give a better showing – especially if they’re fighting from defensive positions. I think you’re right about them opening up to ALLIED forces if we can stop the Germans spoiling things!
Right now the Germans have few troops in Italy, they’ll probably rush some reinforcements to the region – mostly in the south - when/if Sicily is invaded. But there’s no fortified defenses yet, & if the campaign is run correctly there won’t be time either.
It takes a long time to get troops from the sea, disembark them, organize them, rail them, get them to the front, de-rail them, load up on trucks, and drive to the battle zone before they can deploy and engage the enemy. All the while all the Germans have to do is use the rails and roads they already control. Northern Yugoslavia is relatively friendly, and the South Tyrol is inhabited by Italians given the land by Mussolini after Hitler ceded it to Italy, giving Mussolini a political victory and ending any chance of him ever standing with the Allies pre-war. These are NOT Italians ready to fight the Germans.
AndyF said:
It’s probably not feasible, but imagine the 10th Army getting to Italy to find that the Alpine Line is already in place... manned by the Allies
The Allies could never make it. The Germans are too close. They'll draw on their reserves, the Home Army, and the mobile forces in the West. Later on, even troops from Norway and Denmark. Hitler isn't so crazy at this point as to allow his most important political ally to be destroyed because he won't release forces from elsewhere, even on the Russian Front. After all, he did this during Citadel OTL.
AndyF said:
Right around now, the available US regular troops pre-war should be training the new volunteers recruited/drafted since 12/07/41; the first batch should be ready soon. Assuming that the US industrial might have tooled up enough to supply them properly, that’s a lot of trained soldiers that only need combat experience & this is the way to give it to them; a campaign where the number of enemy ground forces is limited. Secure the Western Med first by taking Sicily first, then... Yes, I would imagine that the Italian-Americans in the ranks could be immensely useful there
They might stiffen Italian resistance to the Germans too...
I shudder to think what could happen to the US Army engaging the Germans in 1942. We all know what happened OTL.

Against the Italians, along with collapsing Italian morale the Americans do have the cultural advantage stemming from 19th-20th century Italy's national policy of mass emigration to the New World (the USA and Argentina, mostly, IIRC). With so many Italians having relatives in the USA, OTL they were even less enthusiastic about fighting Americans than they were the British. One of the reasons resistance in Sicily against Patton's troops melted so quickly (of course, he wasn't given the hard jobs of securing Syracuse and Mt. Etna, as Monty was).
AndyF said:
I’d favour Northern Italy; with fast enough advance or a landing at Trieste, it also rules out the Germans setting up the Alpine Line or a variation thereof.(1) There’s the option of further landings in Western Yugoslavia IF the US will go for it (since it’s likely heading for Germany not deeper into the Balkans).(2)
NOOOO! :O Not Roundup... throwing green US/Allied troops into Bocage country? Sheesh! Also I don’t think we’ve got 48 Divisions yet...
(3)
1) Trieste? The Allied sea lanes going up the Adriatic would be a shooting gallery. And IIRC, Trieste isn't any better a choice for an amphib strike than Venice! And it's in a natural bottleneck. No breakouts.
2) No rail lines, no major ports, lots of political troubles.
I honestly think the initiative falls back to the Germans with Sicily/Sardinia/Corsica/the Aegean Islands secured. Where do they bolster the defenses? Paging Major Martin...
3) The idea about Roundup (late in the year 1943) was only in terms of very limited objectives (securing the Normandy Peninsula), and then let the Heer bash away. Make the Luftwaffe come out too. This with the assumption that Hitler is still fully committed to Citadel and is as over-defended all along the Med as he was OTL in Norway.
AndyF said:
I don’t think they’ll do that somehow, do you? The Soviets are the German’s main enemy right now, they’re only looking for mischief from the Western Allies at the moment. Although that will change rather quickly...
I agree. But in terms of Hitler's attention, D-Day turned it West for good. He always got his "Western Briefing" first following the invasion.
AndyF said:
Not necessarily. Take Southern Italy first, then you have land-based air cover to help keep local air superiority. What have the German/Italian navies got to stop naval forces? Coastal craft only by now, maybe a few U-boats. So we’re worried about coastal guns? What else are the BB’s for now?
An invasion force with a heavy escort & carrier backup could proceed at best speed up the Adriatic to perform the landings.
That's a LONG-long way up the narrow restricted waters of the Adriatic, especially through the straits between the heel of Italy and Albania.. Remember, it's not just big shiny battleships and aircraft carriers that have to get through. Its vulnerable troop transports, and slow combustible supply ships. All coming in a steady stream that must be heavily defended, with the Germans justing sitting there in Yugoslavia calling in the air strikes.
That depends on who gets there first – see above. If you land forces in the area around Trieste & take the port as a priority target, then establish a good defensive perimeter? That plan goes out the window. It’s 300 miles from Trieste to Vienna/Bratislava...
And as I have said, they have to get there. Brooke would have a coronary at the thought of this "Gallipoli Squared".
AndyF said:
Alright, so I might be deviating onto the slightly optimistic side, but there’s no great reason why Salerno has to be the limit of amphibious landings if the Allies have taken Sardinia & Corsica.(4) The extension of air cover means the assaults can extend all the way up the Western (maybe even the Eastern (5)) coastline.
Either way, we don’t want to still have forces sitting in Italy when the war ends if we can avoid it; those troops could be better somewhere else. And it’s less optimistic than Marshall going straight for Roundup in ‘42;(6) what if he’d got his way? :O
4) EXACTLY. That was my point all along. The Italians wanted the Allies to land in Rome, but with a starting base of Sicily that was impossible, Salerno was their absolute limit of effective fighter range. ITTL, they have longer range, so Rome might be doable. It might also be Anzio Redux. Even Mark Clark freely admitted that his forces from Anzio could have easily taken Rome. And he was also quite certain that the four divisions involved in the invasion would have been absolutely destroyed in the overwhelming counter-attack which did in fact come.
I worry that there is an awful lot of OTL thinking in terms of German capabilities. Who's to say Hitler doesn't say: "Screw the Leningrad operation! Take everything we have in that sector, withdraw whatever isn't needed to defend a shortened defense line well outside the city, and send the rest to Italy! ABSOLUTE HIGHEST PRIORITY!!

I can afford to not take one destroyed city!
I cannot afford to lose Il Duce! Not because of the cowardice of his worthless people!" That's Hitler. For once, thinking with his heart. Yes. He had one. At least when it came to the man he admired throughout the long years he toiled to rise to power himself.
5) You'll never get me to agree to that.
6) I miscommunicated that, sorry. When I say "Roundup" I MEAN 1943. I never use that word for 1942. Then I mean "Sledgehammer". Which is, I agree, suicide.