NELSON MANDELA has embarked on his triumphant North American tour and it is fitting that he should be received with honor and enthusiasm. He is the world's most famous former political prisoner. He has undergone extraordinary personal privation for his people. He is leading them, after their terrible journey through racial prejudice and oppression, towards the light of freedom. In our celebration of Mr. Mandela's progress, however, we must not forget the other remarkable player in the current South Africa drama. This is Frederik de Klerk, the white president who took the initiative to free Mr. Mandela, and who - in South African terms - has shown extraordinary boldness in moving towards change and reform.
Both Mandela and De Klerk deserve commendation. They have turned against extremism both black and white and embarked on a quest for dialogue and accommodation. Insofar as the United States has any leverage, it should be even-handed in support of them.
But the message Mr. Mandela has brought obliges the United States to take sides. He is arguing vigorously for the retention of economic sanctions against South Africa.
That, says his African National Congress, is the kind of pressure that has been effective in the past upon the ruling white regime, and it is what is needed to keep it moving in the direction of liberalization.
Mr. de Klerk argues that the regime has shown enough proof of its good intentions to warrant the lifting of sanctions. He has taken his message abroad and seems to have been making some headway in European capitals.
In South Africa itself, the feeling about sanctions is mixed. The sanctions have had a negative effect on the economy, which has long been white-dominated.
But one of the significant developments in recent years has been the mobilization of black economic power. Some liberals, like Helen Suzman, argue that it is one of the most significant factors for political change and that it is unfortunate that it is being crimped by the sanctions.
There is not much doubt that the continued sanctions are politically damaging to President de Klerk. He is in a Gorbachev-like situation. He is the would-be reformer who needs help from abroad if he is to keep his restless supporters in line.
White right-wing zealots disapprove of his concessions to the African National Congress. Some 50,000 of them vowed under Pretoria's Voortrekker Monument last month to regain what De Klerk had ``unjustly given away.'' Neo-Nazi factions are arming to fight for white rights.
Right-wingers dub February 2, the day De Klerk announced the lifting of restrictions against outlawed organizations, ``Red Friday.''
Right-wingers sent a somber signal to De Klerk recently when they almost captured a hitherto safe government seat in the Umlazi by-election in English-speaking Natal province.
What would be helpful for De Klerk would be tangible international recognition - like the lifting of sanctions - which would convince white supporters that his policies of moderation are paying off.
In other words, De Klerk argues he has moved dramatically enough to warrant some reward in the shape of sanction-lifting. Mandela argues that the sanctions must remain to make sure whites go all the way to establishing racial equality.
In the United States, the political forces opposed to lifting the sanctions are strong. They will be buoyed by Mr. Mandela's current visit, and the publicity that will generate.
But the Bush administration cannot overlook Mr. de Klerk, the man in the background during all this celebration of Mr. Mandela.
Reprehensible though South African's white regime has been for years, De Klerk is a new voice and a new force. If he is not to be overtaken by extremism from the white right-wing, he needs support.
The White House should be looking at least at gradual lifting of the sanctions as South Africa moves in the right direction after its long years of darkness.