English: The Air Force Security Forces Center, in partnership with the Air Force Small Arms Program Office, has begun fielding the new M18 Modular Handgun System to Security Forces units as part of the Reconstitute Defender Initiative and its effort to modernize weapon systems and increase warfighter lethality. The M18 replaces the M9, which has been in use for more than 30 years. This new weapons system is also projected to replace the M11 used by the Air Force Office of Special Investigations and the M15 used for Military Working Dog training.