What does a nation do, when its citizens enlist in a foreign war?

Many people have been shocked at the terrible shots online of an American photographer being beheaded by a masked IS fighter. That he was obviously British makes large sections of the British public even more uncomfortable. The perpetrator has been called a murderer and no doubt would support any move to bring him to ‘justice.’ The events in the area controlled by the IS are subject to draconian laws that completely reject any philosophy other than ‘their own’ narrow interpretation of Islamic law. If one is not in agreement with that stance or belongs to another ‘faith, be it a branch of Islam or a different ‘ethnic group,’ then there are few choices, the most being, leave, pay protection money or die if one doesn’t convert. Such actions as we are witnessing do not exist in this time alone. During the 1930’s in the Spanish Civil War, many foreigners flocked to the aid of the left-leaning Republican Government as it tried to retain power and the Forces behind Franco, aided by an emerging Nazi Germany attacked the regime. Atrocities were committed on both sides of the fray and even today, many do not forget those times. New Zealanders joined the International Brigade that supported the Republican cause and no doubt witnessed many of the crimes against humanity, including the murder of priests and the decimation of entire villages. Sound familiar! In today’s analogy, we are seeing something similar but on a more vast scale. Combined with the events in Syria, the suffering of large segments of the population in huge areas of Iraq are troubling because the IS does not allow for any negotiation and resorts to methods that have only one goal—the complete takeover of most of the Middle east, stretching from Iraq right through to parts of Northern Africa. Empire building, not unlike so many historical precedents but run by religious despots who will quell any forms of diversity and be completely intolerant of those espousing even a slightly different interpretation of how they would have us worship. There is little that is good about those who control this IS. They are not similar to the forces opposing the Crusaders of old. They do not represent the cultural richness of the Islamic Empire from that time. They do not value education, the arts, science or any other cultural experience. They are narrow minded bigots who would set the region on fire, in order to impose their quasi- political dogma. They should be feared, by all people who wish to live in peace, caring for their families and having a modicum of freedom. History will look back at this time, but I wonder from what bastion! Will the IS have succeeded in imposing its will?