The main doctrines are the doctrines of “containment” and “rollback” of communism.
The “Truman Doctrine” was aimed at limiting the growth of the forces of socialism, which intensified after the Second World War of 1939-1945, exerting continuous pressure on the USSR and other countries of the socialist bloc, and maintaining reactionary forces and regimes.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.