A citizen of the United States who is serving with the forces of a nation with which the United States is allied in the prosecution of a war or military action is entitled to the relief and protections provided under this Act [sections 501 to 515 and 516 to 597b of this Appendix] if that service with the allied force is similar to military service as defined in this Act. The relief and protections provided to such citizen shall terminate on the date of discharge or release from such service.