How do I win The Spanish Civil War?

[Isaac]

The Republicans endure after I have taken Madrid (in spite of their supply lines being crippled), and push through Gallia until my attrition-weakened infantry is unable to hold their defensive lines and collapse.

I cannot let Spain be taken by the Communists.

 

[King Fructose]

Distract them with a big taco truck.

 

[Shidoen]

Plant a Tranny cell in the Communists and watch it fall apart.

 

[Breadbassket]

If its HOI4 wait for the Carlists and Anarchists to pop up and make life even more miserable for everyone involved in the conflict.

 

[Open Window Maniac]

You leave Spain because if either the Commies or the Fascists win, the average peasant loses no matter what.

 

[Isaac]

If its HOI4 wait for the Carlists and Anarchists to pop up and make life even more miserable for everyone involved in the conflict.

I will try this strategy next attempt. A defensive strategy in the Eastern Front, and a minor offensive in the Basque

 

[Wine em Dine em 69 em]

Can’t the Pope do something?

 

[Isaac]

Can’t the Pope do something?

He already did.

https://www.vatican.va/content/pius-xi/en/encyclicals/documents/hf_p-xi_enc_19370319_divini-redemptoris.html

 

[Underperforming]

Go for the next victory point?

 

[Creep3r]

Destroy the enemy's paella reserves and tomato fields.

 

[Kosher Dill]

DO YOU WANT TO PLAY GLOBAL SPANISH CIVIL WAR?

A STRANGE GAME. THE ONLY WINNING MOVE IS NOT TO PLAY.

 

[Divine right to rule]

I hope you are using the "plan offensive" decision, otherwise you get a giant attack debuff.
Otherwise, you can avoid the split with the Carlists if you take the right focus-tree path. Going down the Franco or Falangist route should give you the path to something like "merge the parties", if you do that before the Carlist Uprising happens, they stay with you while the Republicans still have the split with the Anarchists. Use that and take out the Anarchists first, then you should have little problem mopping up the Republicans in the southwest.