What happens when Billy sees the movie going backwards in Slaughterhouse-Five?

Watching the war films in reverse, Billy Pilgrim sees war
as restorative and peaceful. The film's action, going backwards, becomes truly inverted.
Instead of planes shooting each other they suck bullets out of one another. Instead of
dropping bombs to destroy cities, planes suck the bombs into their cargo chambers and
make the cities safe. 

The bombers opened their
bomb bay doors, exerted a miraculous magnetism which shrunk the fires, gathered them
into cylindrical steel containers, and lifted the containers into the bellies of the
planes.… The steel cylinders were taken from the racks and shipped back to the United
States of America, where factories were operating night and day, dismantling the
cylinders, separating the dangerous contents into minerals … [which] were then shipped
to specialists in remote areas. It was their business to put them into the ground, to
hide them cleverly, so they would never hurt anybody ever
again.

This passage demonstrates at least two
things. First, the nature of warfare is subtly explored. War is seen to be mechanical
and rather blindly destructive. The machines of war are shown to be products of a
military-industrial system, "manned" by automatons. The violence of war is given a
plain-spoken, factual treatment (albeit in reverse). Second, the role of perspective is
emphasized. 

Perspective is a major thematic
element of the novel. Here we see an implied statement that if only we could look at war
differently, we may be able to avoid its horrors. If we could see the mechanisms of war
clearly, perhaps we could assert our humanity against its machines. These concepts are
only implicit, but are clearly present in the passage and can be found elsewhere in the
novel as well.