Ways to weaken the Nationalists early in the Spanish Civil War?

I'm trying to come up with ways for an early Republican victory to happen, as by 1938 the momentum seems to have been too for against them. My main ideas so far:

1 - If the Soviets pulled their support from the Republic early in the war, would this make French direct intervention any more politically viable for Blum? This could also weaken the PSUC thus leading to a more 'complete' revolution with more land seizures and decentralized collectivization.

2 - Is there any possibility that the Republican governments/local governments especially in Catalonia would arm the people preemptively a few days earlier than OTL, thus preventing rebel army units from rising up at all in some areas?
 
WI unionized railroad workers went on strike, selectively preventing Franco from moving troops and supplies by land?
Sure Franco was supported by the Condor Legion, but moving supplies by air is frightfully more expensive than moving them by land and you can only deliver a fraction of the tonnage.
Similarly, WI unionized long-shore men went on strike and refused to unload ships containing Franco's supplies?
Remember that most unions have Communist leanings and routinely stick up for the oppressed working class. Many unions openly oppose fascist governments and encourage union members to vote against right-wing politicians.
 
WI unionized railroad workers went on strike, selectively preventing Franco from moving troops and supplies by land?
Sure Franco was supported by the Condor Legion, but moving supplies by air is frightfully more expensive than moving them by land and you can only deliver a fraction of the tonnage.
Similarly, WI unionized long-shore men went on strike and refused to unload ships containing Franco's supplies?
Remember that most unions have Communist leanings and routinely stick up for the oppressed working class. Many unions openly oppose fascist governments and encourage union members to vote against right-wing politicians.

I feel like that already happened to some extent, though it would be hard for railroad workers in a Nationalist zone to maintain a strike against a fully armed military force.
 
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