THROUGHOUT their history, Americans have spoken out against oppressive or misguided policies by other governments. That is not to say that the United States has always readily fulfilled its own highest aspirations. Its long struggle to overcome slavery - and racism - is one example. But the larger point is that the symbol of Liberty standing with a raised torch, signifying freedom and dignity for each individual, continues to have special meaning for millions of Americans.
It is this sense of idealism - coupled with rising frustration over current US policy toward South Africa - that to a large extent explains the increasing numbers of demonstrations around the United States protesting South Africa's segregationist apartheid policy. A number of people, including congressmen, have been arrested in such protests. Meantime, in Washington, Bishop Desmond Tutu, the black South African Anglican who recently won the Noble Peace Prize, told a House subcommittee that current US policy toward Pretoria will not work. At the same time, two moderate-to-conservative Republican lawmakers, Sen. Richard Lugar , new chairman of the Senate Foreign Relations Committee, and Sen. Nancy Kassebaum, recently sent a letter to President Reagan expressing concern about US policy toward South Africa.
The United States has an obligation to remain true to its own highest ideals and to do so in a consistent, fair way. The present administration in Washington has often noted violations of human rights in communist-led nations. It has put private - and even public - pressure on nations with which it has special ties, such as El Salvador; the US has made some progress in curbing rights violations in that nation.
The administration is under increasing pressure to speak out more openly about violations in the Philippines and South Korea. In the latter, calls for a more forthright human rights policy are expected to intensify now that opposition leader Kim Dae Jung is returning home after a stay in the US.
The Reagan administration, for its part, argues that its current policy of ''constructive engagement'' toward Pretoria is close to achieving a breakthrough regarding eventual independence for Namibia. Also, the administration argues that it is effectively, albeit quietly, pushing Pretoria to make internal reforms. Yet the protesters in front of South African government offices around the US say that such quiet pressures are not working, underscored by the South African government's detention of 20 or so black labor leaders.
One does not have to condone violations of laws against foreign embassies to note that there are many avenues of pressure against Pretoria that could be exerted by Washington. Foreign embassies, of course, must be protected. That was a point brought home to all Americans during the Iranian hostage situation. But the other side of the coin is that the administration should speak out more directly against blatant rights violations when they occur in nations that have commercial or other links with the US. Washington, for example, could say that it expects an acceleration of gradual enfranchisement for blacks in South Africa. There is the not-so-small matter of landing rights for South African aircraft in the US. As a last resort, there is the issue of gradual, selective disengagement from South Africa over a period of time.
Ironically, the administration may find itself increasingly isolated on the South African issue. At least five US states and some 13 cities now have requirements barring investment of public funds in companies doing business with South Africa. Washington, D.C., recently enacted a provision giving preference to firms that do not conduct business with South Africa. And considered in this regard, the recent letter to President Reagan from Senator Lugar suggests that the concern about current US policy is moving into the American mainstream - a point that should not go unnoticed at the White House or the State Department.