Upon graduation from the Naval Academy on June 5, 1930, Greene was commissioned a second lieutenant in the United States Marine Corps and ordered to Marine Officers' Basic School at the Philadelphia Navy Yard.
After completing Basic School in June 1931, Greene served for a year at the Marine Barracks, Portsmouth Naval Shipyard, Kittery, Maine.
In July 1932, he completed the Sea School at San Diego, California, and joined the Marine Detachment aboard the USS Tennessee.
Returning from sea duty in March 1934, he served briefly at Pensacola, Florida, and Quantico, Virginia, before reporting to the Marine Barracks, Naval Air Station Lakehurst, New Jersey, that November.
He was promoted to first lieutenant the same month.

Except for a temporary assignment at Edgewood Arsenal, Maryland, where he completed a course in the Chemical Warfare School, Greene remained stationed at Lakehurst until March 1936.
After that, he served at the Marine Corps Recruit Depot, San Diego, until he sailed for Guam in October 1936.
He was stationed there until June 1937, when he embarked for Shanghai, China, to join the 4th Marine Regiment.
In September 1937, the 4th Marines became a part of the 2nd Marine Brigade and Greene was promoted to captain.

Along with his unit, Greene was commended for performance of duty while attached to the defense forces of the International Settlement during the Sino-Japanese hostilities of 1937 and 1938.
Upon his return from China in August 1939, he entered the Junior Course, Marine Corps Schools, Quantico.
He completed the course in May 1940, then took command of the 1st Chemical Company, 1st Marine Brigade, sailing with it that October for Guantanamo Bay, Cuba.
While there, the brigade was redesignated the 1st Marine Division.

Returning with his unit in April 1941, Greene served at Quantico and New River (later Camp Lejeune), North Carolina, as assistant operations officer, 1st Marine Division.
In November 1941, he was ordered to London, England, as a Special Naval Observer.
During that assignment, he attended the British Amphibious Warfare School in Inverary, Scotland, and the Royal Engineer Demolitions School in Ripon, York.
He was promoted to major in January 1942 and returned to the United States the following month.

Named Assistant Chief of Staff, G-3, 3rd Marine Brigade, in March 1942, Greene sailed with the brigade for Upolu, Western Samoa, the following month.
He was promoted to lieutenant colonel in August 1942 and remained on Samoa until November 1943 when he joined the V Amphibious Corps in Hawaii.

For outstanding service as assistant chief of staff, G-3, Tactical Group One, during the planning and execution of the Marshall Islands invasion, Greene was awarded his first Legion of Merit with Combat "V".
Following the disbanding of the group in March 1944, he joined the 2nd Marine Division as G-3, earning a second Legion of Merit for outstanding service in this capacity prior to and during combat on Saipan and Tinian.
He remained with the 2nd Division until his return to the United States in September 1944.

In October 1944, Greene was appointed officer in charge, G-3, Operations, Division of Plans and Policies, Headquarters Marine Corps (HQMC).
He held that post until July 1945, then served as executive officer, Special Services Branch, Personnel Department.
In April 1946, he was ordered to Little Creek, Virginia, as G-3, Troop Training Unit, Amphibious Training Command, United States Atlantic Fleet.
While there, he was promoted to colonel in February 1948, with rank from August 1947.

Detached from Little Creek in June 1948, Greene reported to Pearl Harbor that August as G-3, Fleet Marine Force (FMF), Pacific.
He returned from that assignment in June 1950 and for the next two years was Chief of the Combined Arms Section, Marine Corps Schools, Quantico.
He also served briefly as Chief of the Coordination and Evaluation Section there, before entering the National War College, Washington, in August 1952.
He graduated in June 1953 and the following month became Staff Special Assistant to the Joint Chiefs of Staf
Upon graduation from the Naval Academy on June 5, 1930, Greene was commissioned a second lieutenant in the United States Marine Corps and ordered to Marine Officers' Basic School at the Philadelphia Navy Yard. After completing Basic School in June 1931, Greene served for a year at the Marine Barracks, Portsmouth Naval Shipyard, Kittery, Maine. In July 1932, he completed the Sea School at San Diego, California, and joined the Marine Detachment aboard the USS Tennessee. Returning from sea duty in March 1934, he served briefly at Pensacola, Florida, and Quantico, Virginia, before reporting to the Marine Barracks, Naval Air Station Lakehurst, New Jersey, that November. He was promoted to first lieutenant the same month.
Except for a temporary assignment at Edgewood Arsenal, Maryland, where he completed a course in the Chemical Warfare School, Greene remained stationed at Lakehurst until March 1936. After that, he served at the Marine Corps Recruit Depot, San Diego, until he sailed for Guam in October 1936. He was stationed there until June 1937, when he embarked for Shanghai, China, to join the 4th Marine Regiment. In September 1937, the 4th Marines became a part of the 2nd Marine Brigade and Greene was promoted to captain.
Along with his unit, Greene was commended for performance of duty while attached to the defense forces of the International Settlement during the Sino-Japanese hostilities of 1937 and 1938. Upon his return from China in August 1939, he entered the Junior Course, Marine Corps Schools, Quantico. He completed the course in May 1940, then took command of the 1st Chemical Company, 1st Marine Brigade, sailing with it that October for Guantanamo Bay, Cuba. While there, the brigade was redesignated the 1st Marine Division.
Returning with his unit in April 1941, Greene served at Quantico and New River (later Camp Lejeune), North Carolina, as assistant operations officer, 1st Marine Division. In November 1941, he was ordered to London, England, as a Special Naval Observer. During that assignment, he attended the British Amphibious Warfare School in Inverary, Scotland, and the Royal Engineer Demolitions School in Ripon, York. He was promoted to major in January 1942 and returned to the United States the following month.
Named Assistant Chief of Staff, G-3, 3rd Marine Brigade, in March 1942, Greene sailed with the brigade for Upolu, Western Samoa, the following month. He was promoted to lieutenant colonel in August 1942 and remained on Samoa until November 1943 when he joined the V Amphibious Corps in Hawaii.
For outstanding service as assistant chief of staff, G-3, Tactical Group One, during the planning and execution of the Marshall Islands invasion, Greene was awarded his first Legion of Merit with Combat "V". Following the disbanding of the group in March 1944, he joined the 2nd Marine Division as G-3, earning a second Legion of Merit for outstanding service in this capacity prior to and during combat on Saipan and Tinian. He remained with the 2nd Division until his return to the United States in September 1944.
In October 1944, Greene was appointed officer in charge, G-3, Operations, Division of Plans and Policies, Headquarters Marine Corps (HQMC). He held that post until July 1945, then served as executive officer, Special Services Branch, Personnel Department. In April 1946, he was ordered to Little Creek, Virginia, as G-3, Troop Training Unit, Amphibious Training Command, United States Atlantic Fleet. While there, he was promoted to colonel in February 1948, with rank from August 1947.
Detached from Little Creek in June 1948, Greene reported to Pearl Harbor that August as G-3, Fleet Marine Force (FMF), Pacific. He returned from that assignment in June 1950 and for the next two years was Chief of the Combined Arms Section, Marine Corps Schools, Quantico. He also served briefly as Chief of the Coordination and Evaluation Section there, before entering the National War College, Washington, in August 1952. He graduated in June 1953 and the following month became Staff Special Assistant to the Joint Chiefs of Staf
Wallace M. Greene