The 1970s witnessed significant changes in the international situation. The balance of military forces between the two super-powers of the Soviet Union and the United States developed in a way favorable to the former. While the U.S. strength was weakened and its status as a hegemonic power met with challenges as a result of its long years of overseas expansion, especially it was deeply bogged down in the war of aggression against Vietnam, the Soviet Union, by capitalizing this opportunity and intensifying its arms expansion, stretched its hands everywhere on the strength of its rapidly expanding military might. There emerged in the Soviet-U.S. rivalry a situation with the Soviet Union on the offensive and the United States on the defensive. In order to maintain its global hegemony, the U.S. made readjustments in its foreign policy and carries out a strategy of retrenchment in Asia and opened the door to Sino-U.S. relations with the aim of freeing itself from indo-China and concentrating its efforts in the defence of Europe which is its key area.
To continuously promote the world situation so that it moves in a direction conducive to peace and stability and favorable to the people of various countries, Chairman Mao Zedong pointed out during his meeting with Henry Kissinger in 1973 that as long as we share the same goal, we will not do harm to you nor will you do harm to us and we should work together to counter Soviet hegemonism. We hope the United States would strengthen its cooperation with Europe and Japan and draw a parallel line linking the United States, Japan China, Pakistan, Iran, Turkey and Europe. This is unity against the Soviet hegemonism or the "Strategy of forming an alliance against an opponent".
In February 1974, Chairman Mao Zedong set forth his strategic thinking of the division of the three worlds. He observed, "In my view, the United States and the Soviet Union belong to the first world. The in-between Japan, Europe and Canada belong to the second world. The third world is very populous. Except Japan, Asia belongs to the third world. So does the whole of Africa and Latin America". At the 6th Special Session of the UN General Assembly held in April 1974, Deng Xiaoping expounded the strategic thinking of Mao Zedong on the division of the three worlds. He pointed out that after protracted trial of strength and struggles, the various types of political forces are currently undergoing drastic division and realignment. "From the perspective of the changes that have taken place in international relations, the world today in fact has three sides or three worlds in existence which are mutually related as well as contradictory. The United States and the Soviet Union belong to the first world. Developing countries in Asia, Africa, Latin America and other regions belong to the third world. And the developed countries in between the two belong to the second world". Deng Xiaoping also expressed that China was a socialist country, a developing nation, and it belonged to the third world. The Chinese Government and people firmly supported all the oppressed peoples and nations in their just struggles. He declared that China was not and would never be a super-power in the future.
Mao Zedong's strategic thinking shed light on the fact that the two super-powers were then the main source of instability and turmoils in the world. Their acts of pursuing hegemonism, power politics, the big bullying the small, the strong bullying the week and the rich oppressing the poor gave rise to strong opposition and resentment by countries of the third world. As a member of the third world, China firmly supported the third world countries in their struggles against hegemonism and struggles waged by countries of the second world against interference and control by the super-powers. China was firmly opposed to the policy of expansionism pursued by the super-powers and carried out the policy of uniting with and struggling against the United States with emphasis on striking at Soviet hegemonism thus effectively restraining the expansionist forces of the Soviet Union.