Spanish-Portuguese conflict during World War Two

Did Salazar know this? Because that isn't a good idea for an dictator: to have a shadow government without him ready and waiting elsewhere. They might just decide that 'hey, we don't need that guy in Lisbon' and have the infrastructure in-place to back that up.

One thing to remember, Franco died "peacefully" in his old days because he did not support the nazis or italian facists.

THis wasn´t because he was a nice guy (he wasn´t) but because his country was broken, complete broken by the civil war.

So, either portugal start a war with spain (how?) or there is no war at all.

one thing about spain, it was fully dependend on food supply in that time. Basically Franco would starve 1/3 of his people to death if he start a war - and loose the american food relive spain got.

Really, you need some significant changes to the spanish civil war.
Say, the war ends in 1937 with an easy victory, but this also means that a lot lessons from the war is not done for the german army, airforce... or the russians. This has consequences for the OTL ww2, huge consequences. Also italy is benefited if it is not spending so much money and ressources in this civil war. 

If the war ends as OTL, you have no war with portugal from the spanish side. 
If you do it vicversa, say portugal attack spain, things are different.
Portugal would propably loose the british support, so if the spanish - with german help crush portugal (easily) they are the attacked ones. For germany this mean bases at the atlantic free from british bombers, more air support for german subs and more ports to reach. This make the war for UK a bit harder, but i can´t see em supporting an attacking portugal against spain in the time from 1939-42. After this, well this could be and the butterflies would be immense, but it is no shortcut to victory. The path through portugal and spain is way to hard, the casulties worse and - if spain is attacked by the allies - again without need - the spanish people will fight hard against the invaders. The costs for the allies would be higher. Another bad thing, if portugal is mad and attacks between late39 and early 41 this could mean that the germans take out portugiese azores (or the spaniards do that)... this could bite the allies later, with no air bases here the allies have the need for more long range bombers, maybe more carrier task forces to close the gap.

But you need first the point why portugal attacks spain. Spain would not - with OTL till end of civil war in 39 attack portugal, never. Only if the nazis "win" the war, invade UK.. then they could - as a partner (who helped closing the mediterain) hope for portugies bounty. But that is ASB, cause with OTL build up, no sealion could happen.

Hi,

yes, me thinks too that Salazar wouldn´t do it.
But even more so Franco, because his country was ruined by the civil war.
So basically we have a plot  with two cautious leaders/dictators, who would avoid war as much as possible if victory isn´t clear.
For Franco this mean - if UK had surrendered or german forces advance into London (succsessfull Sealion, well, yes - ASB), for the portuguise that the allies had moved an army or two into portugal, ready to strike against spain. 

Having Portugal due what ever reason be at war with Germany and have Franco being afraid that the British might use Portugal as a staging erea for a invasion of his country.

Well, portugal was neutral, really had a focus for that.
In the same time in 1943 Salazar gave cover for british convoys and allowed US bombers to cut the route to africa.
Later the Azores were used as an airbase for the allies, but still he was neutral. 

i really can´t see this changing. Only if allies troops enter portugal (for that you need to remove Salazar) the germans would react - by immense pressure onto Franco to stop this. 

Only if Spain (Franco) support a german assault on Gibraltar he would be in a war with UK. If he does this (why? - OTL he didn´t) he could later try to invade portugal. I just can´t see this happen as it cut off Spain from its urgently needed food supplies from the USA. Without you loose 1/3 of the spaniards by hunger. Germany could not feed the spanish people, even if they have the wish to do so. 

Maybe someone finds a more realistic plot in this?

Avenging Salazar by subsuming Portugal into Spain? Something like that from Franco?
Therefore, a blatant act of international aggression and Portugal under clear attack. That seems to work. 

I think we are world-building here!