Well, as it stands now they’ve been beaten back in other regions so they’ve stretched themselves pretty thin. Right now, there are some war hawks in Washington advocating for military intervention so that’s probably the next issue since it’s clear the TPLF isn’t going to win this one.
But for the sake of argument, if TPLF did make it to Addis and got rid of Abiy somehow the whole country would be at war. Most Ethiopians are aware of the neocolonial designs of the West so there’s an energy there very similar to Adwa. For all this portrayal of TPLF as the underdog it’s actually Ethiopians that are feeling that with the Imperial West ganging up on us.
In terms of what their fighting for, for themselves personally they’re simply trying to regain control of the country after Abiy sidelined them in order to bring much needed reforms to the country. If they can’t retain control then they want the Ethiopian state to disintegrate so they can fulfil the ambitions of their manifesto and create a larger state out of pieces of Ethiopian and Eritrean land.
For the West, this has to do with the the proxy war with China and the Horn of Africa Tripartite agreement between Ethiopia, Eritrea, and Somalia which seeks to create a more equitable relationship between regional states of the Horn and the outside world by means of closer economic, political, and military cooperation. This is a direct challenge to Western hegemony in the region. An independent Tigray wouldn’t be a viable state at all since Eritrea would still be hostile and pretty much the whole Ethiopian state would be the same. Moreover, the TPLF at their core are classical tribalist dictators so they would have no interest in helping the people on the ground. They know better than anyone that Tigray by itself wouldn’t be able to survive as an nation state. An independent Tigray would only survive as a neocolonial puppet of the West used to drive a wedge between Ethiopia and Eritrea a la Israel and the MENA region.
I’ll just add this: one of the biggest reasons why Eritrea has been the way it has been for all these years is because of the existence of the TPLF threat. Had there never been a TPLF in place, Eritrea most likely would’ve developed far more and would probably even practice liberal democracy or some other pre prescribed West approved political system. But since the TPLF was an existential threat to the Eritrean state they kept up a very hardline stance as a means of survival. Adding this with the TPLF overthrow of the moderate ICU political movement will put things into perspective on who the actual terrorists and ethnic cleansing genocidal maniacs are. So indeed, the TPLF is a primary reason for underdevelopment in the Horn and should be widely considered the largest neocolonial force on the continent.