When President de Gaulle begins his visit to Latin America in three weeks, he will be making his boldest bid for leadership of a separate bloc of free nations since France began its strategy of independence.

That is why U.S. relations with Latin America are likely to look different next month, and a good deal less cordial than when President Johnson and Mexico's Adolfo Lopez Mateos meet in Los Angels today. Despite disagreement on the use of Colorado River water and recognition of Red China, U.S. Mexican relations represent the smoothest side of our hemispheric affairs. The two countries have amicably settled the Chamizal border dispute, and Mexican Alliance for Progress projects have been successful.

But the conversations in Palm Springs-or at least the communiques-are likely to gloss over the uglier problems: Guantanamo, Panama, and above all wide-spread Latin American doubts about the new administration's sensitivity to the area's needs.

Precisely what remains hidden today, however, is what we should expect de Gaulle's visit next month to unearth. The General is hoping that Latin uneasiness with U.S. pressures on Panama after the Canal Zone riots and South American distaste at Johnson's "over-reaction" to minor provocation at Guantanamo will push many of the southern continent's leaders toward the French camp.

Most of all, de Gaulle suspects that if he can offer economic support and an attractive political alternative to the single-minded leadership of Moscow or Washington, many Latin American nations would consider joining him.

De Gaulle he laid his groundwork carefully: Five members of the French Parliament are currently touring Latin America, emphasizing the advantage of closer cultural and economic relations with France. Last week, de Gaulle announced with some fanfare that Germany and France would cooperate on aid to Latin America, giving increased credence to his claim that alternatives to dependence on the United States exist. Finally, he has recognized Communist China, a step that appeals to both Mexico and Brazil. These two countries have hesitated to extend recognition, fearing U.S. reprisals. But when de Gaulle visits Brasilia and Mexico City next month, he is likely to point out that the ban on recognition has been broken, and to offer Mexico and Brazil this symbolic opportunity to assert their independence.

Even if de Gaulle does not succeed in cutting the umbilical-cord to the north in a single blow, he is likely to give it a couple of hard twists. Regardless of what economic aid he can offer, the General is a sympathetic figure to Latin Americans of almost every political hue. His military uniform, and the order and prosperity he has brought to France appeal to the rightists. The grant of Algerian independence and his neutralist foreign policy appeal heavily to the left. Most of all, he has led a small country in dignified and reasonable resistance to the dogmatism of the United States.

But de Gaulle hasn't won this chance to bid for leadership in Latin America without help. A great deal of credit for any realignment de Gaulle achieves should go to Lyndon Johnson, whose insensitivity to Latin American opinion is only rivaled in recent years by the efforts of the Eisenhower Administration.

First, Johnson ignored the sixty prominent Latin American delegates to the third Pan American Interparliamentary Conference. Many of these leaders had journeyed to Washington specifically to hear assurances that the "special relationship" between Latin America and the U.S.-built up during the Kennedy Administration-would continue. Johnson never spoke to them.

Then, the Inter-American Economic and Social Council elected a new executive committee to head the Alliance for Progress. Johnson payed no public attention to this meeting, either. Finally, he met one afternoon with the Finance Minister of Colombia, Carlos Sanz de Santamaria, who will preside over the Alliance executive committee. But no communique was forthcoming, and the two failed to pose for front-page news photographs as Kennedy so often did.

Although the Johnson Administration should not be judged on three months in office, it is impossible not to draw inferences from what the President has done so far about his interests and abilities. In Latin American affairs, LBJ has given de Gaulle a chance to break the cold war alignment and to form his own independent bloc. Whether or not de Gaulle succeeds, whether or not de Gaulle's position has merit, the chance seems not only from the General's diplomatic daring. It also seems due to Johnson's ineptitude.