Donald Blackburn (1916 - 2008) ) was a United States Army officer who, throughout a long career, was a specialist in insurgency, counterinsurgency and special operations before that was recognized as a specialty, and certainly before it was a prestigious area in the U.S. military.
He became a U.S. Army reserve second lieutenant in 1938, and was assigned to duty in the Philippines in 1940 to the 24th Infantry at Fort Benning, Ga. In December 1941, he was a battalion-level U.S. adviser in the 12th Philippine Infantry Regiment.
Filipino-American resistance to the Japanese
After the Bataan Peninsula fell to the Japanese in April 1942, he refused to surrender, and formed a guerrilla unit on the Philippine island of Luzon, which became the 11th Philippine Infantry Regiment, along with another U.S. special operations legend, Russell Volckmann. He later explained that he managed the stress of a hunted behind-the-lines operator by hard labor, such as chopping wood. 
According to another guerrilla leader, Robert Lapham, he thought, at first, they were other "empire builders", but he was wrong, and Volckmann and Blackburn built a serious organization, especially when more senior U.S. officers were captured. They built a major and effective guerrilla organization, working well with both Americans and Filipinos. This regiment, although commanded by a U.S. officer, was commanded by Blackburn, and a regimental commander was normally a colonel, which the Filipinos certainly recognized. Lapham observed that Volckmann, Blackburn's commander, operated in a more remote area than other guerrilla units, and felt safer in keeping detailed records. After the recapture of the Philippines, the work of Volckmann's unit was better documented and thus became more visible to senior U.S. officers. . Lapham also said there were frequent arguments over jurisdiction between his unit and Volckmann's, which probably was good education for Blackburn.
Blackburn and Volckmann had escaped from Bataan and joined the guerrilla movement of Colonels Moses and Noble in northern Luzon, who were later captured in June 1943. Following an abortive uprising in the fall of 1942, they had hidden among friendly natives in Ifugao Province, where they assembled a band of renegade Filipino soldiers and gradually reestablished contact with other groups.
Volckmann took command of the movement in northern Luzon and soon demonstrated that he had learned much from the mistakes of the earlier commanders. These lessons learned would eventually find their way into U.S. army doctrine of separating the guerrilla force, underground and auxiliary. He avoided the temptation to attack the Japanese, focusing on recruiting and organizing underground and auxiliary forces to support regular troops or guerrillas in an eventual U.S. invasion, as well as conducting special reconnaissance providing intelligence to theater command.
He was quite aware of Mao's dictum that the "guerrilla swims among the people as the fish swims in the sea". Volckmann, assisted by Blackburn, mediated factional conflicts, but also was willing to attack private-enterprise bandits. They conducted intensive counterintelligence and executed Japanese collaborators, so that the surviving enemy supporters fled.
After local security and support were established, Volckmann and Blackburn established the precedent for current doctrine, in which the guerrilla combat organization stays separate from the intelligence collection network. The former has a tactical and the latter has a strategic role.
The guerrilla organization had seven districts, each under a commander, often American, who organized a unit comparable to a Philippine Army regiment, a colonel's command. The district commander also was responsible for maintaining civilian support.
At the end of the war, Blackburn was the youngest full colonel in the United States Army, which was not quite sure what to do with a combat-proven 29-year-old colonel. As an indication of the contemporary career dead end that was special operations, twenty years later, he was still a colonel, with the longest time in grade of any colonel in the Army. 
Post-WWII before Vietnam
His first postwar command, although not an especially prestigious one, was the commanding officer, 3rd Training Regiment, Fort Jackson, S.C. In 1957, he was assigned to Military Assistance Advisory Group, Vietnam (MAAG-V), where he was the senior U.S. advisor to the Vietnamese regional commander for the southernmost part of Vietnam, around the Mekong Delta.
Next in October 1958, he took command of the original U.S.-based 77th Special Forces Group (later redesignated the 7th SFG) where he prepared United States Army Special Forces personnel for deployment to places including Southeast Asia.
Vietnam War: MACV-SOG
Blackburn, once the youngest colonel in the U.S. Army and now, the colonel with the longest tenure at that rank, became the second commander of MACV-SOG. For special operations at the time, this was an unusual case of putting "the square peg in the square hole"; most of the commanders had no experience operating intelligence collection or covert action as an insurgent in an area controlled by a hostile government. Those, however, were exactly the things he did in the Philippines.
Later in the war, he was the Special Assistant for Counterinsurgency and Special Activities (SACSA) to the Joint Chiefs of Staff, most notably during Operation IVORY COAST, the attempted rescue of American prisoners of war from the camp at Son Tay in North Vietnam
- Norling, Robert (1996), Lapham's Raiders: Guerrillas in the Philippines, 1942-1945, University Press of Kentucky, p. 104
- Lapham, p. 111-113
- Laphan, pp. 119-120
- Hogan, David W., Jr. (1992), Chapter 4: Special Operations in the Pacific, U.S. Army Special Operations in World War II, Center for Military History, Department of the Army, CMH Publication 70-42
- Shultz, Richard H., Jr. (2000), the Secret War against Hanoi: the untold story of spies, saboteurs, and covert warriors in North Vietnam, Harper Collins Perennial, Schultz, pp. 52-53