Spanish-Portuguese conflict during World War Two

So you think it will drag everyone in rather than be localised? War in the Iberian Peninsula would be costly for all.

That sounds reasonable. Big commitment for all then.

The only way that i see something like that happen, it's that someone different from Franco is the leader of Spain (maybe Sanjuro don't die) and bring the nation in the war at the side of the Axis and decide to launch an attack towards British aligned Portugal to unify the penisula

I think, apart from the fact that both states were right wing at least semi-fascist states and the help Portugal gave to the Spanish fascists, the big problem was the terrible state Spain was in after the civil war. Apart from widespread opposition to the regime the country was shattered by the conflict.

Its possible that a different Spanish ruler might decide to show fascist gratitude [i.e. none] by attacking Portugal. In that case Britain might or might not support Portugal depending on the circumstances. Churchill would definitely want to but say between June 40 and June 41 that would be very difficult given the lack of a powerful army and the way the navy was stretched. Especially since it would give Hitler and Mussolini an excuse to send forces into Iberia and threaten Gibraltar. On the other hand supporting Portugal would, even if Portugal fell, mean that the Portuguese overseas empire with its useful bases would be available. Also I believe that Britain had plans to occupy the Canary's if Spain joined the Axis. As such while the Iberian mainland would be available for Axis subs and a/c to operate from, logistics allowing, which would be bad the availability of the Canary and Azores and the like would enable air patrols over a markedly larger area of the Atlantic.

Also while I can't see any British help saving Portugal if the Germans intervene things change from say 1943 when with the Americans tooled up the option of landings in Iberia, at least forcing the Germans to garrison the region. Furthermore Spain would need a lot of economic help, including food, which was one reason it stayed neutral OTL as it depended on imports from the US and that Germany would struggle to supply much.

As such, if Spain did attack Portugal and get Axis help it would almost certain 'win' but it could backfire for the Axis and Spanish in the longer run.

  Quite possibly.  It would liberate an ally and also have considerable military potential.  Giving an easier access to the continent and drawing the Germans into a conflict further from their centre of power, hence making it more difficult for them to supply.  Also it would help in winning the battle of the Atlantic by removing Axis bases and getting new allied ones.  Getting past the Pyrenees would be a problem but you could then see another amphibious landing to bypass them.  [Mind you if no landing in N Africa technically Vichy France might still exist which would cause complications for both sides.]

  Actually I have read that Franco was of course aware of the allied armada for Torch entering the Med and had a very nervy period as he feared the allies were targeting Spain and was very relieved when they sailed on eastwards.  

  On the 1st pretty much as we discussed there.  There would be a number of butterflies of various sizes. 

  On the 2nd one interesting.  Only had a brief look through but does seem strange, to the modern eye at least, that Portugal itself had pretty much the same population as its territoriality much larger African colonies.  Can't see them being able to oppose a Spanish/German invasion but the navy and bases would definitely be useful for Britain and the allies causes.  Also there were Axis ships basically isolated in some Portuguese ports, most noticeably Portuguese Goa that provided intel to German raiders.  The film The_Sea_Wolves was based on a true life story where those were 'taken out' unofficially but if Portugal joins the allies that's no longer a problem.