In a narrow vote, the U.S. Senate Foreign Relations Committee this week approved harsh sanctions against South Africa because of that regime's apartheid practices. Despite the approval, it's unlikely the bill will get off the Senate floor, and that's for the best because the measure simply goes too far.

The bill, similar to one that passed the House last month on a 244-132 vote, would cut off virtually all U.S.-South Africa trade. In addition, it would compel all American firms to pull out of South Africa.But the 10-9 committee vote - mostly along party lines - means that the legislation lacks bipartisan support and would not be able to survive a threatened filibuster in the few days left in this year's session of Congress. Neither are there enough votes to over-ride a presidential veto.

The bill takes a questionable idea - that U.S. sanctions can force other countries to behave the way America wants - and tries to impose that action while somehow still remaining friends with South Africa.

Just look at some of the flaws in the proposed measure:

- It would not only impose sanctions, but would require the president to retaliate against foreign firms taking advantage of U.S. sanctions to sell to South Africa. That's unworkable. It would put the U.S. at odds with its trading partners and violate international trade agreements.

- It would block U.S. exports to South Africa, except for agricultural products, an important political consideration for some members of Congress. If South Africa were punished by a trade embargo, why would they help American farmers by buying U.S. food?

- It would prohibit U.S. intelligence agencies from working with South Africa, but would magnanimously allow the South Africans to give America intelligence date on Cuban military forces in Africa. Why would South Africa bother with such a one-sided deal?

- It would ban all imports of South African goods, with the exception of certain strategic materials. If the U.S. cut off trade, why would South Africa respond by selling America badly needed minerals? And if South Africa cut off such sales, it would add $1.8 billion to the Pentagon defense budget, as well as leaving the U.S. without access to some vital strategic materials.

All in all, the U.S. would suffer as much as South Africa. And sanctions historically have proven to be an inept way to change behavior. The stubborn Afrikaners are not going to alter the distasteful practice of apartheid because the U.S. is pushing. There are ways they can push back. Keeping doors open, using encouragement, persuasion, and help, may take a long time, but in the end will pay greater dividends.

Sen. Alan Cranston, D-Calif., argued that if the U.S. fails to impose harsh sanctions, it will be seen as a sign of support for apartheid.

Such an argument fails to convince. The U.S. doesn't have total trade sanctions against the Soviet Union, for example. Does that mean the U.S. supports communism? Of course not.

Unfortunately, much of the trade sanction voting has nothing to do with South Africa as such. It has more to do with taking a moral position and looking good with certain groups in an election year.