Protocols to the North Atlantic Treaty of 1949 on accession of Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia : message from the President of the United States transmitting protocols to the North Atlantic Treaty of 1949 on accession of Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia : these protocols were opened for signature at Brussels on March 26, 2003, and signed that day on behalf of the United States and the other parties to the North Atlantic Treaty.