Matt Wright (firstname.lastname@example.org) writes:
I looked up the word 'fortress'; it means something used for military purposes only, permanently garrisoned. A fortress is used to create a hold in an area that presumably isn't under control yet. in the early days of the Forerunner, maybe they came into our galaxy and used the halos to gain a foothold, much like Spain, France, and England created fortresses in the New World, and area that was not under their control (yet). Many people (including me) have assumed that the Forerunner were not expecting biological lifeforms to be on Halo. This may not be entirely true, since Covenant and Human forces could battle away happily on the surface until the flood were released. Perhaps there were restricted areas that only robots were allowed past, unless there was a breech of security. The fortress world would have been self- supporting, as some fortresses in our history have contained towns or living quarters, food supplies, etc. This might explain the similarities between earth and halo, though it seems that the Covenant experience no adverse effects due to the environment, so maybe their home worlds are the same or similar to earth. So, perhaps the forerunner kept the Flood locked up, and lived their merry lives on the surface trying to gain control of the galaxy. History has a way of getting lost, though, so perhaps once the galaxy was conquered, or in the end wiped clean by the halo's, the Forerunner left the Halo's and inhabited the galaxy as they saw fit. So, perhaps the Forerunner, in some form, are the Covenant now.
Why release the Flood? You can destroy anything and everything in the galaxy anyway. Only if you wanted to inflict pain would you do that.