It's called The War of the Worlds, so warfare must be important, right? Well, for the humans, this is definitely a war. The British military gets involved in a big way and there's death and destruction on an unparalleled scale. But for the Martians, this might not be war at all. It could just be an exercise in pest control before they move in. As the artilleryman puts it, "It never was a war, any more than there's war between man and ants" (2.7.32). There's a term that people use today to describe this type of war, a war in which the two sides are not evenly matched: "asymmetric war." In The War of the Worlds, the fact that only one side is really at war is part of what makes the warfare theme special (that is, insulting to humans).
The War of the Worlds depicts war as part of the natural order of life: species evolve and compete, and war is simply a form of competition.
Because we see war from a non-soldier's point of view, we get the idea that war interferes with life.