Managua, Nicaragua — The coordinator of the ruling junta, Daniel Ortega Saavedra, stands before a crowd of residents in a poor Managua neighborhood. He speaks about civil defense preparations for a United States invasion of Nicaragua, which he and other Sandinista leaders are predicting. And he periodically asks the residents questions to which they are obliged to answer in a chorus of ''yes'' or ''no.''
The boyish-looking Ortega shouts into his microphone, ''Do you want peace?'' The crowd answers, ''Yes.''
''Do you want war?'' Ortega asks. ''No,'' the crowd says.
Evening meetings between Ortega and Managua residents and suburbanites are an institutionalized system of communication between the people and the Sandinista leadership. Biweekly sessions are held in the neighborhoods to give the Sandinista hierarchy direct contact with the Nicaraguan people. When Ortega finishes his talk, the residents approach the microphone with written questions.
Tonight the meeting has a special significance. In attendance are about 80 doctors, nurses, and health professionals from the US. They are in Managua for a conference on health issues. In the past few days they have seen a variety of high-ranking Sandinista officials. Ortega has assured the crowd that the visitors ''support the revolution.''
The questions, which are usually prefaced by praise for the Sandinista government and a short explanation of how the questioner is a good party member, are soft. Residents ask about combating the ignorance of neighbors who do not understand the revolutionary process or plead for better garbage collection or telephone service.
Many of the questioners direct their queries about US aggression to the North Americans in the audience. Dr. Paula Braveman, one of the organizers of the health conference, condemns the Reagan administration policies in Central America and compliments the interchange between the Sandinista leadership and the people. She promises to go back to the US to work for the Sandinista revolution.
Visiting North American groups considered sympathetic to the Sandinistas have become major propaganda tools for the government here. These groups receive special treatment by the Sandinista press office, which usually makes access to government officials difficult, if not impossible, to the international press corps.
North American visitors are urged by the Sandinista government to go back to the US and, in the words of one government official at the meeting, ''tell the American people the truth about Nicaragua.''
On a narrow dirt street near the meetinghouse, a few residents sit on the steps of their homes, attempting to find relief from the hot, stagnant air.
''The people that go to those meetings,'' says one woman, ''are already Sandinistas. They belong to the Sandinista organizations in the neighborhood. For them it is a required event.''