My son recently saw a picture of a war graveyard in Europe, probably France, where he noticed that the graves were mixed with Stars and crosses. He asked why the Jewish dead were not buried in a special place away from the Goyim. I could not answer, tho’t that they were in a hurry. As he pointed out, it was known that the dead were Jewish so why did not the chaplain separate them? What is the halacha in cases like this?
Your son's question happens to touch upon an issue which happened in our own family. Before I was born, my father's brother was killed in action in the Normandy invasion in WW II fighting as an American soldier. He was buried in Normandy, France as your son probably saw in the picture. My grandparents of blessed memory made efforts to bring his body to a Jewish cemetery. After 13 years bureaucracy they succeeded and he was brought to final rest in a Jewish cemetery in New York. I don't know what influence Rabbis had as army chaplains in WW II, to see that Jewish soldiers be buried in a Jewish cemetery. However, I found a publication called "Responsa in War Time" published by the COMMISSION ON JEWISH CHAPLAINCY, in which Rabbi Aryeh Lev wrote in December 1947: "In this country,[USA] bodies of Jewish soldiers may be prepared according to the wishes of the parents. The body is brought to the denominational undertaker and properly placed in the coffin ready for burial either at the home cemetery or a national cemetery. Overseas and especially in time of war such elaborate preparations cannot be made. In war conditions the body is buried as soon as possible so as to avoid decay or despoiling by the enemy. Burial parties work even under fire and they could not be expected to carry about with them talleithim to place on the Jewish dead." In Normandy alone more than 9000 US soldiers (Jews and gentiles) were buried, we can fully understand that which Rabbi Lev wrote. Having said that, I wish to explain what is the position of Halcha on this issue. Indeed a Jew may not be buried near a gentile. This is according to Torah law. (חת"ם סופר (יו"ד חלק ב' סימן שמ"א, בשו"ת מנחת אלעזר (חלק ב' סימן מ"א), דעת כהן סי' רא,) Even though bodies normally cannot be exhumed, however in these circumstances it may be done. I am unaware of the distances between plots in US military cemeteries so I can't offer practical information if it is necessary. It is also difficult to judge the distance from photos. However, if there is a distance of 4 amot, which are about 2 meters from each side of the burial place or according to Rav Yisraeli zt"l (שו"ת מראה הבזק, חלק א , סי' סז) even if there is a hedge with the height of about a meter there it is considered a partition and the body may remain there. May the memory of the fallen soldiers be for a blessing. Besorot tovot and happy Purim.