The French are convinced that in Central America the Reagan administration pursues, despite its vaunted anticommunism, the kind of policies that in fact give an advantage to Soviet infiltration. They are equally convinced that Washington ignores what the causes of communism are really all about and consequently deals with subversion the wrong way. It follows, the French say, that Washington's current policies undermine the Western presence in the area. Anti-Westernism may, in turn, endanger vital French interests. Should this happen, the French do not exclude that a serious confrontation between Paris and Washington might ensue.
Central America represents for the French a test case in North-South relations which they consider the foremost issue in the world today. Beyond ideological principles, they feel directly threatened because the spread of anti-Western feelings, exploited in full by the Cubans and their friends in Central America, is already causing problems in the departments of Martinique and Guadeloupe.
The two West Indies islands form an integral part of the French territory, to the same extent as Paris or Marseille; or, for that matter, to the same extent as the islands of Hawaii are part of the United States. The French cannot, therefore, remain indifferent to a threat to these islands.
Washington, the French say, has so far failed to understand their position. They mention two typical examples. Paris has received broad hints from Washington not to meddle with what is going on in the US's backyard. It was also told that France fails to appreciate the extent and nature of the communist involvement. France finds that neither position has a leg to stand on.
France's two islands are located in the general area of conflict, and this, Paris feels, more than justifies French involvement. They are no ''backyard,'' but France itself. As to misconstruing communism, the French recall that President Francois Mitterrand has spent the past 30 years fending off communist snipings. No one, they say, knows the communists better or is more hostile to them. The French see the US as failing to understand that their position in Central America is dictated by an uncompromising anticommun-ism. The main divergences between the two countries concern not the issue of subversion but the most effective way to fight it.
In this respect, the French attitude is founded on three main considerations:
* A refusal to see the conflict in El Salvador and elsewhere in the region in East-West terms. The real causes are economic and social. (In El Salvador 2 percent of the population owns 50 percent of the arable land.) The communists exploit the situation but are not the main cause for it.
* A conviction, embodied in last August's Franco-Mexican declaration on El Salvador, that a military solution being impossible only a political compromise can put a stop to the conflict. This implies a negotiation to which all parties, including the combatants, are invited. The US, the French say, is repeating the mistakes it made in Vietnam when it sought a military solution with the tragic consequences that followed.
* The best rampart against communism and the spread of Soviet influence is for the countries of the region to remain nonaligned. At present, the rule applies in particular to Nicaragua. The chances of preserving Nicaragua nonaligned are not lost. They will be if the US persists in its present policies. The longer the El Salvador conflict lasts, the greater the risk that Managua may gradually drift toward the Soviet camp; a trend that a modest sale of French arms was meant to discourage. There is continuity in the French position: a loan to Managua had been offered by the previous administration of President Valery Giscard d'Estaing.
Another more subtle reason for the French attitude is hostility, traditional since Charles de Gaulle's time, to all zones of influence. Should they accept the principle that Central America falls within the US sphere of influence, the French say they could not very well object (as they do and quite loudly) to the Soviet presence in Afghanistan or interference in Poland.
The French are anxious to be on the best of terms with the Americans and hope that their contrasting policies in Central America will not cause deep frictions.