4th Tank Battalion 4th Tank Battalion ( 4th Tanks ) is an armored battalion of the United States Marine Corps reserve . Their primary weapon system is the M1A1 Abrams main battle tank and they are part of the 4th Marine Division and Marine Forces Reserve . The unit headquarters is at the Navy and Marine Corps Reserve Center San Diego , California but other units in the battalion are located throughout the United States . With six lettered companies , 4th Tank Battalion is the largest Marine tank battalion . Mission . To provide armored combat power for the 4th Marine Division in the amphibious assault and subsequent operations ashore utilizing maneuver , armor protected firepower and shock effect to close with and destroy the enemy . The battalion is also tasked to organize , train , and equip individual Marines and combat ready tank companies to augment and reinforce the active duty component when required to serve as part of the Total Force of the United States . 4th Tank Battalion is a self - sustaining , autonomous unit capable of performing all the tasks of the regular force . History . World War II . The battalion was first formed on May 12 , 1943 at Marine Corps Base Camp Pendleton , California . It was composed , with the exception of 2 officers , entirely of reservists . It was the first unit to capture Japanese mandated territory in the Pacific . It participated in the Battle of Kwajalein , Battle of Saipan , and the battalion ' s last major operation in World War II was the Battle of Iwo Jima . Late in 1946 , a group of World War II veterans began meeting at the Marine Corps Recruit Depot on a volunteer basis . This became the formation of the first organized Marine Corps Reserve unit in San Diego . The unit was officially designated as the 11th Tank Battalion in 1947 and became home for a headquarters and a tank company . Korean War . In July , 1950 , the unit was activated for the Korean War . Those members with sufficient experience as tankers formed the nucleus of B Company , 1st Tank Battalion , at Camp Pendleton . The 4th Tank Battalion motto is " 53 days . " When Marine reservists were activated for the Korean War , it was just 53 days until they participated in their first combat action , the landing at Inchon in September 1950 . San Diego reservists served with this unit , participating in the landings at Inchon and Wonsan , fighting to Hagaru - Ri and Koto - Ri . B Company remained in Korea until the armistice . In May 1952 , the unit was reactivated in San Diego , now bearing the name 1st Tank Battalion , and headquartered at MCRD . In 1958 , the battalion was transferred to Camp Elliot as a more appropriate location for tank operations . In July 1963 , the battalion was redesignated as 4th Tank Battalion , Force Troops , Fleet Marine Force , USMCR . The 1960s through to the 1990s . Between November 1990 and January 1991 , 4th Tank Battalion was mobilized in support of Operation Desert Shield and Operation Desert Storm . Elements of the battalion were " in country " and combat ready within 32 days of activation . During the fighting , Bravo Company engaged Iraqi tanks in combat on February 25 , reporting 34 enemy tanks destroyed or disabled . Global War on Terror . During Operation Iraqi Freedom portions of the battalion were activated and deployed to Iraq , and to Afghanistan during Operation Enduring Freedom . Most recently , the Marines of Echo Company , based out of Ft . Knox , deployed to Afghanistan to conduct route clearance missions throughout Helmand Province from April 2012 to October 2012 . Echo Company was attached to the 1st Combat Engineer Battalion based out of Camp Pendleton , California .