Twas the Condor Legion that bombed Guernica. Hitler and Mussolini both gave assistance to Franco, sending soldiers and airmen.
The Manic Street Preachers song, If you tolerate this then your children will be next, is based on a Spanish Civil War propaganda poster which showed Fascist planes bombing women and children with the words If you tolerate this then your children will be next.
How right they were as the people of Warsaw, Rotterdam, Coventry, Clydebank, London soon found out.
HH
There is a good documentary on PBS about the Scottish people who volunteered for the International Brigades and fought for the Spanish Republic. It's called The Scots Who Fought Franco.
If ye are interested in all this check oot the Glasgow woman Ethel McDonald.