Well the space marines are part of the Imperium, so the Imperiums enemies are the space marines enemies. After the Taros campaign stalled, the imperium has not really done mush to the tau. They are definatly not allied.
The eldar are also not allied with the Imperium. Apart from the odd Radical inquisitor, the imperium wants nothing to do with the eldar, and the eldar only interact with the imperium if it is part of their grand plan (re-creating the Eldar empire). |