How did the U. S. strategy in Vietnam change under Nixon? What was the result in the change of strategy?

The main goal of Richard Nixon's Vietnam policy changed the focus from the search of victory to an honorable exit for the United States, "peace with honor" as president Nixon used to tell the public and the media, and to give a large responsibility to the local South Vietnamese government and army in the fight against Communists.

He also formulated a concept that came to be called the Nixon Doctrine, which meant that the U. S. would not get directly involved in fighting in proxy wars, but it would give allies a larger role in fighting against communist movements or guerrillas in Asia (or elsewhere), and that they would get weapons, supplies and U. S. advisors.

While the war in Vietnam went on and although he was willing to use overwhelming force in some cases, Nixon conducted diplomatic talks with the North Vietnamese in Paris, which concluded with a peace accord that allowed the withdrawal of most American troops in 1973. He also attempted to get the support and good will of China to get a peace agreement (given China's important support for the Vietnamese Communists) while he visited Beijing in 1972.