The Polish flag is raised during a ceremony outside of NATO's Brussels, Belgium, headquarters, where the flags of all member nations are flown, following the country's accession to NATO, March 16, 1999. The Polish flag is raised during a ceremony outside of NATO's Brussels, Belgium, headquarters, where the flags of all member nations are flown, following the country's accession to NATO, March 16, 1999. SHARE: Download: Full Size (0.47 MB) Tags: Photo Essays Credit: VIRIN: 745612-S-EOZ61-644.jpg Photo Gallery