The main difference between President Carter's foreign policy and the policies of Presidents Nixon and Ford was that Carter's foreign policy was based more on idealism and less on force/self-interest than the policies the other two pursued.
Perhaps the most famous example of Carter's more idealistic foreign policy was his decision to make a treaty giving the Panama Canal Zone "back" to Panama. There was no need for the US to do this, and you can argue that it makes us less secure, but it seems more like the right thing to do.
It is hard to say if Carter was more or less effective. Nixon's policies were not able to win the Vietnam War, but they were able to make better relations with Red China. Carter's policies managed to get the Camp David Accords made, but were unable to prevent the Iran Hostage Crisis.
There were differences between President Carter’s foreign policy approach and the approaches of President Nixon and President Ford. President Nixon believed that the United States could enjoy a relaxation of tensions with Communist China and with the Soviet Union. He believed that if we dealt positively with one country, it would lead to a better relationship with the other. Thus, President Nixon visited Communist China and began to develop trade with them. The Soviet Union, fearful we might become friendlier with Communist China than with the Soviet Union, began to negotiate with us. This led to the SALT I agreement with the Soviet Union. President Ford, who was in office for about two years before the next election, followed similar policies to President Nixon. However, President Ford wasn’t able to keep South Vietnam from being taken over by communist North Vietnam.
President Carter tried to achieve some lofty goals with his foreign policy. He was able to get the leaders of Israel and of Egypt to sign a peace agreement, known as the Camp David Peace Accords. Some people felt these countries would always be at war. President Carter wanted to improve relations with Latin America. The Panama Canal Treaty was one way to achieve this. However, President Carter struggled mightily in getting our hostages freed from the Iranians in 1979. He also took a firm approach in dealing with the invasion of Afghanistan by the Soviet Union. We gave weapons to the Taliban, and we boycotted the 1980 Summer Olympics held in Moscow. Recently, we have fought the Taliban in the war on terrorism.
Both Presidents had some successes with their foreign policy. It is hard to say if one was better than the other. Both had successes, and both had setbacks. Each President did what he thought was best for our country at that time.
Carter’s foreign policy reflected his emphasis on having the United States observe higher moral principles. This was different from Nixon’s foreign policy which was seen to mimic or reflect the enemy’s principles. Carter’s policy sought to resolve issues internationally by responding differently as compared to how the other countries reacted. Ford, on the other hand, took a defensive approach to foreign policy and focused on developing the country’s strength through international alliances and sometimes overlooking some of the vices in the allies. This was a sharp contrast to Carter’s administration which sought to evaluate even the allies’ conduct with regards to issues such as human rights. Ford’s administration chose to retain Kissinger who was Nixon’s Secretary of State in a move that showed Ford’s intention to further pursue Nixon’s foreign policy. In this regard, Ford and Nixon's foreign policies had major similarities which sharply contrasted with Carter's policies.
For too many years, we’ve been willing to adopt the flawed and erroneous principles and tactics of our adversaries, sometimes abandoning our own values for theirs. We’ve fought fire with fire, never thinking that fire is sometimes best quenched with water. Carter.