On August 11, 1981, Raúl Arana and Orlando Bolaños from the UDN met with Legion leader Enrique Bermúdez in Guatemala City, and agreed to unite in a new organization, the Nicaraguan Democratic Force.
A three-man political commission was set up for the FDN, with Cardenal as its coordinator, his ally Mariano Mendoza from the UDN, and Aristides Sánchez from the Legion.
The UDN-FARN became a founding member of the rebel organization Pastora was forming in Costa Rica, the Democratic Revolutionary Alliance (ARDE), on September 23, 1981.
Despite instructions not to attack the border post at El Espino, to avoid offending Honduran authorities who liked to deny that Nicaraguan rebels were based on their soil, they did so.
Back in Costa Rica, UDN-FARN joined the new rebel umbrella group, the United Nicaraguan Opposition (UNO) in June 1985.