(a) The Secretary of Defense is authorized, under such regulations as he may prescribe, to provide, without expense to the United States Government, transportation from the United States or military commands overseas, and return, on vessels of the Military Sealift Command or aircraft of the Air Mobility Command for
(1) those Girl Scouts and officials certified by the Girl Scouts of the United States of America as representing the Girl Scouts of the United States of America at any International World Friendship Event or Troops on Foreign Soil meeting which is endorsed and approved by the National Board of Directors of the Girl Scouts of the United States of America and is conducted outside of the United States,
(2) United States citizen delegates coming from outside of the United States to triennial meetings of the National Council of the Girl Scouts of the United States of America, and
(3) the equipment and property of such Girl Scouts and officials, to the extent that such transportation will not interfere with the requirements of military operations.