THE FATE OF the struggling, bereft former Portuguese colony of Mozambique may not weigh greatly in the geopolitical scales, but this southern African country has become the object of an intense ideological tug of war. The argument is between those who consider Mozambique Marxist and Soviet-oriented, and therefore a fit candidate for liberation under the precepts of the Reagan Doctrine, and those who see in President Joaquim Chissano a lapsed or lapsing Marxist whose pragmatism and, in particular, whose desperation to save his country from South Africa and underdevelopment make him a fit candidate for Western cultivation.

We think the evidence supports the view that Mozambique is a country well worth the West's reaching out for. Certainly President Chissano, who was received by President Reagan yesterday, is making a big push to strengthen and display his Western ties -- even as he takes economic and military aid (but no troops) from Moscow. The truly interesting aspect of the American argument over Mozambique, however, lies not so much in its terms, which are familiar, as in the principal parties to it. The parties are not, as you might expect, Ronald Reagan and liberals to his left. The parties are Ronald Reagan and conservatives to his right. As a country where an ostensibly anticommunist resistance is going on without American backing, Mozambique has become a symbolic cause for hard-core conservatives. They demand that President Reagan conduct there the rollback policy he is conducting elsewhere in places where Marxists came to power in the past decade.

To his credit, Mr. Reagan is resisting these urgings. His more subtle and pragmatic policy sees Mozambique's Renamo guerrillas accurately as clients of unregenerate South Africans and Portuguese, recognizes the African nature of Mr. Chissano's leadership and welcomes the opportunity for the United States to perform a limited but useful service of diplomatic brokerage between South Africa and Mozambique. The issue comes soon to Capitol Hill in the form of an administration-backed effort to end last year's congressional ban on including Mozambique in a key regional transport project. Among Renamo's champions there are those like Sen. Jesse Helms who appear immovable on the issue and those like Sen. Bob Dole who should know better.