Starship Troopers by Robert A. Heinlein Tuesday 30

'Intelligence believed that prisoners were always taken to Klendathu; the Bugs are as curious about us as we are about them--a race of individuals able to build cities, starships, armies, may be even more mysterious to a hive entity than a hive entity is to us.
As may be, we wanted those prisoners back! In the grim logic of the universe this may be a weakness. Perhaps some race that never bothers to rescue an individual may exploit this human trait to wipe us out. The Skinnies have such a trait only slightly and the Bugs don't seem to have it at all--nobody ever saw a Bug come to the rescue of another because he was wounded; they c0-operate perfectly in fighting but units are abandoned the instant they are no longer useful. Our behavior is different. How often have you seen a headline like this?-- TWO DIE ATTEMPTING RESCUE OF DROWNING CHILD. If a man gets lost in the mountains, hundreds will search and often two or three searchers are killed. But the next time somebody gets lost just as many volunteers turn out. Poor arithmetic... but very human. It runs through all our folklore, all human religions, all our literature-- a racial conviction that when one human needs rescue, others should not count the price. Weakness? It might be the unique strength that wins us a galaxy' (Heinlein 223).

The reason why this passage is important to the story is because it reveals the main character's mindset about the social virtues and responsibilities of his people. The passage also shows how the Bugs, Earth's mortal enemies, are different from the humans in that they seem to lack all care for the individual and live only to serve the whole. The main character also mentions that that lack of individual care is what is the greatest difference between the Bugs and the humans, even though he said previously that a part of being a soldier was to die in order to preserve the whole if need be, a virtue not unlike the mindset of the Bugs.
One question I have about the story is: What is the reason for the war between humans and Bugs?
A question about the plot that I have is: The main character says at the beginning that wanting to rescue individuals may be a weakness. So why does he state at the end that 'It might be the unique strength that wins a galaxy' ?