What was the stance of the Roman Catholic Church on the Vietnam War?

Communism has been an enemy of the Roman Catholic Church (RCC) for a long time, but also capitalism has been a problem. To many people, the Vietnam War did seem like a meaningless war. But Jesus said, "War must come" (see, for example, Matthew 24:6 ). My questions is: Did the RCC take a stand for the Vietnam War or against it? Did they support one side? What was its official reaction?