>>43298068Minor change these days. The High Lords of Terra know the Tau by name, they are considered a major threat and a growing power that puts them above the hundreds of other minor xenos races not worth mentioning in the setting. Mostly because every time they come across other, otherwise harmless, xenos race they absorb them and the Tau grow stronger. The Tau are turning a bunch of little problems into one big problem.
Its not that the Imperium can't be bothered to send more space marines at the situation, its that they cannot afford to. They want to send a massive fleet to wipe out the Tau once and for all, but there are other more urgent matters that need attention first so they are sending what they can spare in the hopes of slowing the Tau down and buying time.
The shift in tone has had to do with recent Tau victories, where before the IoM took it for granted that if they threw any serious firepower at the Tau they would crumple, recent Tau victories over heavily defended Imperial worlds with new superunits like the Riptide have dramatically changed the Imperial viewpoint of the Tau. Now, the IoM isn't entirely sure what it will take to shatter the Tau, but they have realized that the Tau are not just going to wait around with stagnant tech for it to happen.
tldr: 100 years ago, the Tau would have been easily crushed. Now it would actually be kind of difficult and really resource intensive. The High Lords of Terra are fretting over whether they will be able to do it at all in another hundred years or more.
