"The deaths on July 20 of two Americans serving in the Israel Defense Forces (IDF) provided an opening for critics of Israel to compare them to the foreign fighters of the Islamic State... Similar complaints have already called for other governments to criminalize volunteering for Israel to create equivalence to the prosecution of would-be jihadi Islamists. The IDF reports 4,600 foreign 'Lone Soldiers' currently serving, over one-third of whom are American (it is unclear how many hold dual citizenship). Are IDF Lone Soldiers comparable to al-Qaeda-inspired jihadis or the volunteer brigades who joined the Spanish Civil War?" ('Foreign Fighters' for Israel, David Malet, The Washington Post, 22/7/14)
How about both?
As author Christopher Othen reminds us in Franco's International Brigades: Adventurers, Fascists, and Christian Crusaders in the Spanish Civil War (2008):
"Foreign volunteers fought on behalf of General Franco and the Nationalists in the Spanish Civil War for a right-wing cause whose aim was to smash democracy. These assorted adventurers, fascists, and Catholic crusaders were on the winning side, but their role has remained strangely hidden until now. Men from Portugal and Morocco signed on for money and adventure. General Eoin O'Duffy organised 7000 Irishmen in a modern crusade; 500 Catholic Frenchmen fought in the 'Jeanne D'Arc' unit; and 30 British volunteers, including aristocrats and working-class fascists, also took up arms. Romanian Iron Guard extremists died at Majadahonda and an Indian volunteer fought in the fascist militia. There were Russians, Americans, Finns, Belgians, Greeks, Cubans and many more. Goose-stepping alongside the volunteers were fascist conscripts from Germany and Italy, in training for the next world war."