How we cite our quotes:
Up till now neither Caspian nor the others had really been thinking of a war. They had some vague idea, perhaps, of an occasional raid on some Human farmstead or of attacking a party of hunters, if it ventured too far into these southern wilds. (6.17)
War is clearly an important theme in the novel, so it's interesting to see it show up so late. But once the idea grabs hold of Caspian and company's minds, it goes viral and just spreads. Same goes for the novel, since the war will be the bulk of the story to follow.
Caspian nor the others hesitated for a moment: it now seemed to them quite possible that they might win a war and quite certain that they must wage one. (6.21)
Must is the interesting word for us. Why must they wage a war? No diplomacy? What about that duel idea Peter came up with? We're not quite sure the must is earned here. Want maybe.
Thus there was fighting on most days and sometimes by night as well; but Caspian's party had on the whole the worst of it. (7.38)
If you check out our "Tone" section, you'll see that some people have an issue with the novel's tone concerning the theme of war. Case in point: death, violence, sorrow, and mutilation summed up as "the worst of it."