Unlike some other heavy metal albums, this one will definitely survive the first phase of bannings and revisions under the dictatorship of the proletariat, and maybe the second one too. The simple reason is that there are few more powerful anti-war songs than "War Pigs."
While the Beatles associated themselves with flowers, psychedelia and vague talk of peace, Black Sabbath wrote a couple aggressive, pointed and powerful anti-war songs. "War Pigs" refers to our ruling class in its awful splendor during the Vietnam War. Unfortunately to most of the imperialist public, being aggressively, loudly and energetically for peace is a contradiction in terms. When the public thinks of peace, it thinks of little old ladies attending Quaker churches or young wimmin frolicking naked with flowers to "make love, not war." Black Sabbath was one of a few bands to completely break that image and culture (which was positive but not enough) and put forward a more urgent call to peace.
Another classic loud heavy metal song is "Iron Man." It refers to a Vietnam War veteran who returns to the United $tates "to kill the people he once saved." This is in reference to the serial killings done by returned Vietnam War veterans who the public thought of as sick war criminals in many cases based on reporting of incidents in the war. Again, there could hardly be a more powerful indictment of "what goes around comes around."
While the Beatles were singing "if you go carrying pictures of Chairman Mao, you ain't gonna make it with anyone anyhow" and proclaiming it's "gonna be all right," Black Sabbath was singing what a morbid and depressed mood it was in. Especially during the Vietnam War, Black Sabbath was right and the happy-go-lucky folk singers and the Beatles were wrong. It's not appropriate to be cheerful in a light-hearted way in the midst of carnage that you and people like yourself can stop. After the Beatles and the disco upsurge, Black Sabbath became positively disrespectable, the music of high school suicide cults.
To be sure, most of Black Sabbath's music is moody, escapist and morbid. Without political context, it becomes completely wrong, a mere statement of the decadence of imperialism, pure sludge-rock. In the context of the Vietnam War, Black Sabbath was right on. A handful of bands were much more consistently political, but none were more powerful in their art.