So to throw some Allied IPC investment requirements in the European Theater:
What we know is that small invasions aren’t necessarily successful in the long term except in the cases of:
1. Landing some units on N.Africa via Morocco to help secure Egypt if Italy has a somewhat to very successful Northern Africa campaign
2. Seizing Norway and denying Germany the NO.
So to set some parameters:
1. London can churn out 10 units / round to shuck into Normandy. This puts the critical mass of TT at 5, or a 35 IPC investment. This initial investment can be mitigated depending on if the UK can save its two TT. So UK investment in TT for critical mass is 21-35 IPC depending on Germany Round 1 results.
2. US needs at a minimum of 10 TT for an initial landing. This will allow for the US to land with 20 ground units, reinforced by 10 UK ground units in the same round for a total of 30 ground units in Normandy. This will cost the US 70 IPC for the initial landing.
3. In order to maintain the supply lines and hence reinforcements, both the US and UK will each need a fleet to protect their TT investments. The recommendation has been suggested to defend the landings with CV + Ftr and DD as screens. Bombardments don’t seem as valuable in Europe as they do in the Pacific where you’re likely using less ground units on an AA, so I agree with not investing in BB/CR to screen CV or add additional punching power to an AA landing. With that said, I think the decision needs to come down to how many CV are sufficient to support two separate locations where TT will be massing (Off Gib and in the Channel). I’m going to posit that you’d need 3 total for the Allies, where you position yourself based off of Axis Air/Naval Power.
This means 48 IPC of CV. In order to secure the decks, you’re going to need 60 IPC of Ftr. This can be partially offset by the UK and French if you elect to not scramble on G1 and save yourself the equivalent of an entire UK IPC purchase round in Ftr by doing so. So CV + Loaded Ftr is going to cost you at most 108 IPC at at a minimum of 68 IPC if you elect to preserve the starting Ftr in and around London.
4. DD screens appear to be the flavor of choice. I’d wager the safest way to screen yourself is to match the Axis Air / Naval Power with DD on a 1:1 ratio. So for every German Ftr/Tac/Bomber in range, you’ll need 1 DD to absorb a hit while your Ftr slowly grind them out. Same would go for Axis naval presence, particularly SS on a 1:1 ratio. This number can vary greatly, and may not be significantly required for an initial landing if German aircraft are deep in Moscow and out of range. Still, I’d suggest at a minimum of a 1:1 ratio of DD per every CV and Ftr in your Naval stacks. So at a minimum you are looking at a total of 9 DD or 72 IPC worth of DD with no threat present, and in excess of 100 IPC if there are Axis warships or aircraft within striking distance. As this can be split between the UK, and the UK has a “closer” complex right there in London you can merge up on, I’d suggest London do the bulk of the DD purchases.
5. Now that the support is covered for the initial invasion force, you need to consider the actual ground units. The US is going to have at a minimum of 20 units put on 10 TT to land. I’ve found the best investment to be Inf/Art. So for 10 TT that means 70 IPC worth of units for the US. As the UK is in more of a reinforcing position, you have two choices early in Normandy: 10 Inf on 5 TT or 5 Inf, 5 Arm on 5 TT. I do like the Arm option as it gives a bit more of a defensive “ooomph” to an Axis counter attack that may have a decent amount of German Armor in it. Just realize it costs you 30 IPC (which is most of the UK income in 1 turn) to fill 5 TT with. You set yourself back “half a turn” by adding Arm instead of simply doing 10 Inf. Conveniently, the UK will probably be in a position to fill 5 TT with 10 Inf rather easily if the UK purchased 6 of them and 1 Ftr on UK1 to guard against a potential Sea Lion. So you can be “efficient” and kill 2 birds with one purchase that pays dividends later.
6. As you cannot settle for simply the landing itself, you are going to need to prepare the US to start a ferry of new units into Normandy in the successive rounds. This is going to require 5 more TT in the next 3-4 rounds, which you will also have to fill with either Inf, Inf/Art or Inf/Arm to ferry first to Gib, then to Normandy. In short you’re going to need a rotation of 4 sets of 5 TT:
5 TT off Washington DC to start your turn, that you fill with ground units and move to Gib.
5 TT that you move from Gib to Washington DC for next turn’s ground units.
5 TT returning from Normandy to Gib to move to Washington to stage for ground unit pickup Turn+1
5 TT moving from Gib to Normandy to drop off ground units.
Now, you DO have 10 TT from the initial landing, but I have a recommendation that you actually keep those 10 TT off Normandy as if the Germans make a mistake, the US and UK can leapfrog Denmark to Berlin at any given point and you’d rather have the ability to vacate Normandy with 20 US ground units, sack Denmark and open the door to go for the throat in Berlin than to wish you hadn’t sent those TT back to America for more units and lost the opportunity to bring the Germans to their knees.
So, that means once you’ve committed to the landing in Normandy, Turn+3 will require full IPC investment into the Atlantic to establish a system that grinds the Axis down. You need to consider that when you start the invasion in regards to where Japan is positioned. If you interrupt this influx of reinforcements, you may risk everything you built and gained up to this point if you give the Axis a reprieve from the pressure.
So to summarize the initial landing cost:
15 TT = 105 IPC
3 CV = 48 IPC
6 FTR = 20-60 IPC
9 DD = 72 IPC
15 INF = 45 IPC
10 ART = 40 IPC
5 ARM = 30 IPC
Which puts you between 360-400 IPC for an initial landing.
*There is one variable is UK Ftr landing on Normandy. Which the cost is variable based on how soon the UK gets up to speed and can purchase additional Ftr to secure Normandy. From my experience this could be supplemented directly from the FTR on the CV, but if under threat you may be required to safeguard the TT and require additional FTR flying in from London to support Normandy. Anything less than 4 FTR appears insufficient, but much of that is highly dependent on the counter attack you will face from Italy / Germany.
You’ll need additional investment of another 20 TT for the US over the successive 3-4 turn, which runs 140 IPC.
You’ll also need to fill those TT each (Both UK and US) round going forward for the foreseeable future, which this cannot be completely interrupted.
You must deal with Japan early, or not at all. Once you begin the invasion you cannot flip flop for at least 3-4 turns on heavy investments between the Atlantic and Pacific. You’re better off delaying a landing in Normandy by a turn to ensure the US has the assets in the Pacific to stymie Japan for a few rounds.
This is also why I don’t aggressively pursue Japan out the gate as the US. I’d rather have the resources in the mid game to keep Japan at bay until I can start splitting investments between the Pacific and Europe again.
Thoughts, feedback, critiques?