The provisions in this subchapter are in addition to, and are not in lieu of, any other provisions of law or regulations. The sale of firearms in the United States, for example, remains subject to the provisions of the Gun Control Act of 1968 and regulations administered by the Department of Justice. The performance of defense services on behalf of foreign governments by retired military personnel continues to require consent pursuant to part 3a of this title. Persons who intend to export defense articles or furnish defense services should not assume that satisfying the requirements of this subchapter relieves one of other requirements of law.