The main purpose of its activity was to prevent Soviet domination over Poland and to fight communism. Although, the pursuit of those goals was supposed to be largely peaceful, the fact of Soviet domination over Poland and the increasingly hostile and provocative behavior of local communists frequently resulted in WiN having its hand forced and in military confrontation. Although the WiN forces were well-armed and highly disciplined, they could not hope to fight a prolonged guerrilla war against the Soviet Red Army and NKVD units - a fact clearly understood by the leadership. Thus, to the extent possible WiN attempted instead to concentrate not on military action but rather on providing assistance (false documents, money) for former soldiers of Armia Krajowa, NSZ and other Polish resistance organizations believed not to be allied with the Soviets.
It was WiN that first carried the news of the falsification of the 1946 Polish people's referendum in an announcement to the United Nations Security Council. Members of the organization were persecuted by both the Soviets and the local communists. NKVD soldiers and Ministerstwo Bezpiecze?stwa Publicznego agents carried out a bloody war with its 30,000 men in Mazowsze and Lubelskie region. WiN's soldiers liberated many Soviet jails in Poland, and killed collaborators and communist agents. However, the organization was penetrated by Urz?d Bezpiecze?stwa agents, and its security compromised as early as late 1945.
In 1946 new WiN leadership decided to subordinate the organization's structures to the Polish Supreme Commander in the West. Simultaneously, it limited its support for the PSL party (which, at that point, had also been infiltrated by Soviet agents). Thereafter, the organization was run by former members of the Polish Home Army.
WiN was initially divided into three different geographical operational theatres: Western run out of Pozna?, Central, run out of Warsaw as well as Southern, run out of Cracow. By 1946 this was reduced to Central and Southern. In January 1947 WiN called on the PSL to boycott the Soviet sponsored elections and to await intervention by Western Allies.
Despite protestations of the DSZ leadership, recognizing their common origins and similar goals of ridding both Poland and Ukraine of Soviet, WiN engaged in talks with the Ukrainian Insurgent Army (UPA). By spring 1947 in the Lublin region and Podlasie WiN signed an armistice with UPA. Occasionally, WiN and UPA cooperated in destroying communist establishments (for example in a joint May 1946 attack on secret police headquarters in Hrubieszów). Similar agreements were reached in May 1945 in Ruda Ró?aniecka, as well as April 1945 in Siedliska.
In April 1947, many WiN members came out of hiding to take advantage of an apparent amnesty issued by the communist authorities. Instead, many were killed. Members of the organization were accused of plotting the overthrow of the People's Republic along with the Polish leaders in the West such as General W?adys?aw Anders and the CIA. The show trials for most of the leadership took place in 1947. The Communist repression apparatus under Jakub Berman and Stanislaw Radkiewicz exterminated most of the leadership and by 1953 the organization had been destroyed. Nonetheless, individual units continued to fight for Polish independence until 1963.
Information published later indicated that one of the reasons for the failure of the WIN mission to Poland by the Gehlen Organization was that inside information had been provided to the Soviet Intelligence services by "moles" within the Organization. The "Org" was an intelligence agency established in June 1946 by U.S. occupation authorities in West Germany and controlled by the CIA.