The Weathermen sought the violent overthrow of the government and, in their hay day, made no bones about it.
Source: FBI, via Freedom of Information Act
In 1976, the FBI's Chicago Field Office prepared a summary which described the activities of the Weather Underground Organization, also known as Weathermen. This organization described itself as a revolutionary organization of communist men and women. The FBI's analysis of its motivations, beliefs, and international travels are outlined in this summary.
[some excerpts from the 1976 report linking the organization to foreign governments...]
From the moment in October, 1967, when Radio Hanoi announced the formation of the South Vietnamese Peoples Committee for Solidarity with American People (by the National Liberation Front (NLF), the political arm of the Viet Cong) with the objective of establishing relations with "progressive organizations and individuals in the United States," a political front was enjoined in behalf of the national interests of the Democratic Republic of North Vietnam (DRV) (and the NLF), the purpose of which was to intensify the anti-war sentiment in the United States.
From the initial meeting between the Vietnamese and leading anti-war activists held in Bratislava, Czechoslovakia, in November, 1967, to the July, 1969, meeting with leading Weatherpeople held in Havana, Cuba, the influence of Vietnamese representatives on the Students for a Democratic Society (SDS) leadership became sharply pronounced. At the same time, the example of the Cuban revolution became the guide for the emerging American student revolutionary. With an increasing number of trips to Havana where the youthful revolutionary could learn at first hand how to create revolution, the influence of Cuba on the developing WUO [Weather Underground Organization] was enormous.
The WUO obtained their revolutionary methodology from the Cubans and Vietnamese and, importantly, put into practice what they had learned from them. The Weathermen, of course, did not just happen to come about during the June, 1969, SDS National Convention. They fully admit their radical heritage began during experiences gained in SDS and as shown herein their international contacts with representatives of the DRV and NLF which began in 1967 increased their anti-imperialist consciousness so that by 1969 they had solidified their revolutionary commitment to include the maximum optimum of armed struggle. So, when Huynh Van Ba, representative of the Provisional Revolutionary Government of Vietnam (PRG), instructed the WUO to "look for the person who fights hardest against the cops...Don't look for the one who says the best thing. Look for the one who fights," the campus base was forgotten and the WUO began to recruit the greasers and assorted oddments who had displayed their hatred of authority in direct combat with police.
http://foia.fbi.gov/foiaindex/weather.htm