Isla seemed to be attracted to the man willing to take risks....much like her attraction to Laslo.
Given what we know today about the atrocities of the left in Spain’s civil war, that hasn’t aged well; movies like this one, “Sahara”, and “For Whom the Bell Tolls” were war propaganda movies that all included noble Westerners who had helped or fought for the Spanish Republic - which now we know oversaw the murder of 8,000 Catholic priests (including a dozen bishops), 400 nuns, and countless faithful lay people - who continue to be declared martyrs by Popes (and will be for decades to come).
Rick was complicit in that...