The recent massacre of nearly 400 Mozambicans by a South African-sponsored rebel group called Renamo brings into sickening focus the efforts of some Americans, led by Sens. Robert Dole and Jesse Helms, to aid a group until now supported only by the South African government and some disgruntled Portuguese colonialists.

At dawn July 19, hundreds of Renamo guerrillas stormed into the town of Homoine. "Whole families were killed with bursts of automatic weapons fire; children were cut in two by heavy-caliber machine gun fire," reported The Los Angeles Times. "When they exhausted their ammunition, the guerrillas used bayonets and machetes to stab and hack the villagers to death."

Sadly, this massacre was only the latest incident in seven years of brutal maraudings by the Renamo organization in its campaign to oust the Frelimo government of Mozambique, which came to power in 1975 after 400 years of devastating Portuguese colonialism.

For more than nine months, Dole and Helms have been blocking Senate approval of the administration's nominee for ambassador to Mozambique. Their reasons are disagreements with the president's support of the Mozambique government, not any defects in his nominee, career Foreign Service officer Melissa Wells.

For once, the Reagan administration is on the sensible side in southern Africa, supporting the Mozambican government of President Joaquim Chissano with economic and food aid.

Margaret Thatcher's government has just doubled its aid, including military training and equipment. What the Reagan and Thatcher governments understand is that the struggle over Mozambique is not a fight to "roll back communism," despite the fact that the Mozambican government professes socialism and receives Soviet military aid. This beleaguered government is seeking real nonalignment, rooted in cooperative relationships with East and West. Mozambique is following pragmatic economic policies to begin rebuilding its shattered economy, end hunger and reduce the poverty of its people.

Renamo, or the Mozambican National Resistance, was created in 1976 by the intelligence service of the white supremacist government of Rhodesia. Its assignment was to harass Mozambique because of its support for the black independence movement led by Robert Mugabe. Just before Rhodesia became the black-majority-ruled Zimbabwe, the Renamo organization was handed over to South Africa's Department of Military Intelligence.

Thus Renamo's war on Mozambique has never been an East-West question, despite the efforts of Dole and Helms and various right-wing groups to portray it so. In fact, Renamo is part of the apartheid South African government's attempt to destabilize its black neighbors and to ensure that their rail and road lines do not become an alternative to South Africa's own economic stranglehold on the region.

The fact is that although Renamo's foot soldiers are Mozambicans, and some of its leaders former members of the army, it has neither nationalist credentials nor any demonstrated political support inside the country. Instead, it is a tool of the South African government's campaign of destruction and destabilization against its neighbors, including Angola, Zimbabwe, Zambia and Mozambique.

Today several million Mozambicans are threatened by starvation, much of it caused by Renamo's destruction and its attacks on roads, rail lines, schools and health clinics; drought and economic mismanagement are also factors. It is shocking to find Dole putting millions of Africans at risk simply to nail down right-wing support for his presidential candidacy.

Dole should withdraw his support for Renamo and for Helms' efforts to block the nomination of President Reagan's nominee for ambassador to Mozambique. The administration should continue to support the Mozambican government and reject efforts to aid Renamo. The lives of millions of Africans, and the success of U.S. policy, hinge on these sensible measures. The writer is executive director of TransAfrica, a black American lobby on Africa and the Caribbean. "The Reagan administration is on the sensible side in southern Africa, supporting the Mozambican government."