In 1928, was assigned responsibility to set up an advanced training program for the Peruvian Signals Corp, improving the standards for military communications and command and control in the armed forces. From 1929 to 1933, Marín taught at the Officer Candidate School, first as Instructing Captain, then Studies Principal, then Commandant of the school. In 1934 Marín was promoted to Major. He attended the Peruvian War College, receiving graduate-level instruction to prepare for senior leadership assignments and responsibilities. While there, Marín also taught some classes. He graduated at the top of his class, earning the Espada de España. In 1937, Marín returned to Paris, attending France's Superior Officers War College, graduating with honorable mention and the highest grades. When he returned to Peru, he was appointed to a senior position with the Army General Staff, a post he still held during the actions of the Ecuadorian–Peruvian War of 1941. In 1946, Marín was promoted to Brigadier General and appointed Director of the Chorrillos Military School, a position he left in 1947 when the President of Peru, José Bustamante y Rivero, appointed Marín as Minister of War in his cabinet. In 1948, Marín chaired the Commission of Military Institutes, in charge of proposing a new set of fundamental policies upgrading the preparedness the Peruvian armed forces. This led to the creation of a cabinet-level Ministry of Defence in Peru, as well as the creation of the Center of Advanced Military Studies. The CAEM was created in 1950, with Marín as its first Commandant. In December 1952, Marín became Commandant of the School of Applied Engineering. He later created the Leoncio Prado Military School, then was appointed as director of the Chorrillos Military School. In December 1956, Marín was promoted to Major General. He retired from the military in January 1957, though he continued as an academic adviser for the CAEM for three years.
Continued academic career
After Marín's retirement from the military, he did continue working in public academia, building on the work in advanced education he had championed throughout his time with the Peruvian armed forces. Marín was the principal professor at the National University of Engineering, teaching there for 32 years, retiring as Professor Emeritus. He was a professor at the High CommandSchool of the Air Force of Peru, from its inception, and also of the Peruvian Diplomatic Academy. Marín was a member of the National Academy of Mathematical and Physical Sciences, and president of the Institute of Natives Language. Marín died on December 6, 1980.
