In their opposition to American imperialism, radicals pursued many actions. They synchronized protests, helped deserting GIs find safety, strengthened ties with Vietnamese revolutionaries, put the United States on trial for genocide, and even organized international brigades to fight in Vietnam. But at this stage, they prioritized the ideological struggle, which was precisely what Vietnamese officials themselves sought most from their comrades in this part of the world. Indeed, Vietnamese revolutionaries believed that the war would be fought not only in the jungles of Vietnam but on the terrain of ideas. Collaborating closely with Vietnamese communists, radicals in the North Atlantic radicalized the discourse around the war. In fact, by the end of 1967, the general antiwar struggle grew far more radical. Radicals defined the enemy as imperialism, coded their internationalism as anti-imperialism, and revived the Leninist problematic of self-determination. This approach to internationalism became so popular that even those who did not consider themselves radicals adopted some of its core elements. By the late 1960s, anti-imperialism was beating out its many internationalist rivals – such as individualist human rights – to become the dominant way in which activists in the North Atlantic imagined international change.