The terrorist Italian Red Brigades have gone international with their kidnapping of US Brig. Gen. James Dozier, vilified as a ''Yankee pig'' by the guerrillas holding him hostage. Security sources said he was probably undergoing a ''people's trial'' Sunday aimed at extracting NATO military secrets.
A team of American experts sent by President Reagan Sunday quizzed General Dozier's wife, Judith, who was in the apartment when he was dragged away, police sources reported. Dozier had access to secret military information, but a NATO spokesman said he did not know NATO codes or ciphers.
President Reagan sent the experts to work with Italian police and counterespionage agents trying to track down the kidnappers. Italian state television said three of the Americans were Central Intelligence Agency (CIA) agents with knowledge of European guerrilla groups.
The guerrillas who snatched the general from his home in Verona late last week have so far followed the practice of their past political kidnappings.
The sources said they thought General Dozier was facing fierce interrogation about his post as deputy chief of staff for logistics and administration at NATO's Southern Europe Land Forces headquarters in Verona.
The guerrillas issued their first communique Saturday. They made no ransom demands, but branded the Western alliance an occupation army and said the general was being held in a ''people's prison.''
General Dozier's wife made a tearful broadcast Saturday appealing to the Brigades to free her husband.
Despite a massive police dragnet in northern Italy, no arrests had been made as of this writing Sunday.