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This timeline is based on France ignoring what Britain wanted which was non intervention

1936
General Franco revolts and starts the Spanish civil war
Due to there being a more interventionist government in France at the time France helps the Spanish republic and ignores Britain’s call for non intervention Italy and Germany send arms to Franco. Soviet Union and Mexico helps the republic as well
November By this time the nationalists have made fewer gains than they did OTL
December a German boat trying to send arms to the nationalists is sunk by a French ship
Tensions increase and in January 1937 France declares war on Germany Italy does the same in February
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