The Mobile Strike Force (also known as MSF or MIKE Force) was an elite element of the 
US sponsored Civil Irregular Defense Groups (CIDGs) in South Vietnam.  Like the CIDG program, 
the MIKE Forces were under direct US control through the Military Assistance Command Vietnam (MACV).
Initially made up almost exclusively of ethnic minorities, MIKE Force units eventually incorporated 
South Vietnamese CIDG units.  The MIKE Forces operated until the end of 1970 when the CIDG program 
was transfered to the South Vietnamese Government and the MIKE Forces were converted 
into ARVN Ranger units.
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The RP is an abbreviation for Reconaissance Platoon, an integral part of each MIKE Force Company.