President Reagan has a monumental selling job in Latin America if he is to win support throughout the hemisphere for United States policy initiatives in Central America.
That becomes clear as US involvement in the region mounts with disclosure of plans for large land and sea maneuvers (involving at least three major Navy warships and possibly 4,000 US ground troops), expansion of the number of US military advisers in El Salvador (to a possible 125 from the current level of 55 ), and appointment of the special presidential commission on Central America chaired by Henry Kissinger.
These and other US moves are increasingly seen in Latin America as provocative and unwise.
Criticism of Washington grows. It comes from traditional US antagonists like Cuban President Fidel Castro, who calls the Reagan program ''blatant and despicable.'' At the same time, Dr. Castro appears more willing to negotiate on Central American issues than he was a few weeks ago - perhaps because of the strong US pressure in the area.
But that pressure is viewed with alarm by many friendly Latin Americans, some of whom worry as much as Mr. Reagan about the possibility of a Marxist victory in Central America.
How to prevent a leftist victory is what divides the US and its Latin American allies. The Latin Americans favor negotiation and dialogue - and note that while Mr. Reagan says he does, too, US actions seem bellicose.
Dispatching thousands of troops for maneuvers seems inconsistent with Mr. Reagan's promise that ''we're not planning a war.''
To Latin Americans, these signals from Washington are troubling.
Despite President Reagan's assurances this week that there is not as ''much disturbance among our friends and allies'' in the hemisphere over his policy as critics suggest, there can be no mistaking the concern about the policy emerging in Latin America:
* Several hemisphere presidents - Belisario Betancur Cuartas of Colombia is one - openly question whether Mr. Reagan really wants talks and a peaceful solution in light of US plans to stage large military maneuvers in Honduras and naval maneuvers off the Nicaraguan coast.
* The Contadora group, albeit divided in its assessment of the seriousness of the Marxist threat and what to do about it, worries that Reagan merely gives lip service in support of efforts to find a peaceful solution.
* Mexico, although deeply disturbed by the threat of an exploding Central America on its southern flank, has told Washington bluntly that US policies in the area are confusing and wrongly directed - and will not in the end contribute to solving regional problems.
* The appointment of Dr. Kissinger to head the Central America commission has touched off deep concern among Latin Americans who hold him responsible, in some measure at least, for the overthrow of Chilean President Salvador Allende Gossens in 1973.
Latin Americans also say President Reagan's remarks on the region are confusing. In his press conference Tuesday evening, the President pointedly rejected the notion that his Central American actions were a new version of ''gunboat diplomacy.''
Yet Mexico City television commentator Jacobo Zabuldowsky reminded viewers the same evening that only two months ago the President had praised the ''big stick'' philosophy of President Theodore Roosevelt. That philosophy included the concept of gunboat diplomacy.
Mr. Reagan had complained there are too many ''soft speakers'' today, adding: ''If we cannot act decisively so close to home, who will believe us anywhere?''
Such language seems ''saber rattling'' to Latin Americans. The Contadora leaders from Colombia, Mexico, Panama, and Venezuela made it clear two weeks ago that they feel Washington has embarked on a dangerous policy in Central America.
The Contadora group does not minimize the threat it sees from Cuba and Soviet actions in the region. But it wants Washington to ''think through its policy more carefully,'' as a spokesman for Venezuelan President Luis Herrera Campins put it.
The same concern was recently aired at a little-heralded, but significant conference in Caracas that was attended by four influential former Latin American presidents. Washington was taken to task ''for talking peace, but making warlike gestures'' in the area.
President Reagan will hear more of such views firsthand when he and Mexican President Miguel de la Madrid Hurtado meet in La Paz, Mexico, Aug. 14. It remains to be seen whether he will change his opinion.
But he will encounter a Mexican view that differs sharply from his own. Mexican sources say the meeting will include ''plenty of time to air Central American issues and to air our mutually differing positions.''