'OGA is an abbreviation used in the United States to signify Other Government Agency.
In government and military parlance it is often used to speak euphemistically of the Central Intelligence Agency.
These agencies often recruit persons from special operations units in the United States military. Some of these units include but are not limited to Special Forces, the Navy SEALs, 75th Ranger Regiment, and the U.S. Army Scouts, and are often considered to be of Tier-One capability.