In the 21 years of war (1954-1975), confronting an enemy with great potential, economic strength, military power, the Party and State of Vietnam determined that the support of socialist countries is extremely important. In every step of the development of the resistance, especially in the process of negotiating and signing the Paris Agreement, proactively and independently planning policies and guidelines, the State of Vietnam always pays attention to reference. opinions and enlist the approval of socialist countries, especially the two major Soviet Union and China.