This restriction does not apply to VWP travelers whose presence in any of those countries was to perform military service in the armed forces of a VWP country, or in order to carry out official duties as a full-time employee of the government of a VWP country. The Secretary of Homeland Security may waive this VWP restriction if he determines that such a waiver is in the law enforcement or national security interests of the United States. Such waivers will be granted only on a case-by-case basis.