I sometimes wonder whether editors read the stories they are writing headlines for. A headline on page A15 {June 21} reads "Envoy Backs U.S. Sanctions for S. Africa." This sounded like a real sensation. Was Ambassador Edward Perkins actually taking issue with the White House and with assistant secretaries Chester Crocker and Alan Keyes? Then I read the story and found that Mr. Perkins had described last October's sanctions act as having been a success "as a statement of abhorrence by the American people of a hated system."

But I had thought the purpose of sanctions was to help end apartheid, or at least push the Botha government in that direction. As to whether that government has been effected, the ambassador thinks it is too early to tell.

Having just returned from a trip to South Africa, spent with people who are working very hard to end apartheid and replace it with a multiracial democracy, I am satisfied that sanctions and the disinvestment campaign have impeded rather than aided this effort. They have become a major factor in the rise of the ultra-right in the recent election and the hardened line of the Botha government against further dismantlement of apartheid legislation. ARMISTEAD LEE Arlington