The main gain is the Treaty Ports and further from those three other areas to set airbases from the looks of what they offered, Unification support is a large offer for that (or perhaps even then Westminster wanted shot of NI? @ShortsBelfast ), it wasn’t for the material strength that Ireland could add, those wiki numbers are “soft” with nothing more than small arms for the Army (and forget the Reserve figure). Future deployments of an actual Irish Expeditionary Force would depend on a lot of different factors, as for the Irish status in the Empire/Commonwealth, the Free State/Ireland was always a Dominion until the Republic was declared, it’s just pretty much under Dev it was totally disengaged, staying part of the Commonwealth isn’t that hard a POD, or at least an easier one than being involved in WW2.My question is that what exactly does the UK gain here? How does Ireland shift the war? Does the Irish Army take part in North Africa? Do the Australians being sent East earlier? I'm genuinely curious as to what Ireland adds that the US isn't already selling to the Brits. A quick wiki read tells me that the Irish Army at this point was actually quite substantial; 40k regulars and 100k reservists. However, the issue isn't solely numbers; I don't think that Ireland or Britain could really afford to equip that many troops immediately. I think we could see a could Irish divisions being sent off to Egypt or maybe Crete; although cooperation between London and Dublin will be an interesting field to navigate. With the very recent civil war; it'll be very easy to see that the 'Free State' concept is just a dominion with slightly more dignity. Depending on how things go Ireland would likely be a part of the Commonwealth.