Not completely impossible, but very, very difficult.
You are going to need to take some planets from an AI in order to get tech and expand your manufacturing base. On suicidal, the longer you wait the harder it will get. Your best bet is going to be to get two AI's to go to war with each other and then stab one of them in the back. The Altarians and Drath are both bad choices because of their super abilities. You would likely end up at war with more than one AI. That leaves the Iconians (or is that the Korx who are your neighbors?, colors are too close), It would be best if you could get the Altarians to go to war with them (easier to take advantage of the war), but this is unlikely due to their alignment...So I would try bribing the Thalans and Iconians into war. Do the Iconians still have significant numbers of planets without defenses? Is so, let an Iconian/Thalan war play out a few turns (long enough for the Iconian transports to be out of their space and into Thalan space) and rush transports onto these worlds and hope you get enough tech and time to stem any counter attack.
You might also try bribing the Altarians to attack the Drath (not the other way around, you don't want the Drath to badly outnumbered). This will keep them both busy and not looking at you.
Also, if tech trading is on, get anything you can get...
Your odds will largely depend on how badly the Iconians out tech you. click on a couple of the defended planets and see how strong they are. If you can even the tech gap on ship strength with the first planet rush, your odds dramatically improve as it becomes a matter of who can put the largest number of effective ships on the front...Remember they are fighting two wars now. You might also be able to pick up a few more undefended planets by threading transports in just behind Thalan lines and picking up planets that they manage to clear.
If you can come out OK through the first war, you still aren't out of the woods, but this might take you up to 50/50 odds. I would suggest a similiar style rinse and repeat on the second war.
There is one other path here I see as well. A little safer, but not the same kind of gains and it might not be enough at this stage. Bribe the Torians/Drath to go to war with each other. Then declare war on the Torians and take all of their planets that border you and all the planets that are in Drath space. The Drath should effectively screen you from facing the Torian military, so it's pretty safe to do. If they make peace, immediately go in and bribe the Drath to restart the war. If you can't restart the war this way (you should be able to)or the Drath start losing badly, go to one of their southern neighbors and immediately start up a war on one of those borders. The wierd part here is that you will never try to negotiate peace with the Torians, it will simply costs too much until you have gone through at least one more war. If they make an offer and you have pciked up everything useful from them that you think you can get. Go for it...Otherwise, after you have picked up the easy kills, just rely on perpetual Drath/Torian war for defense and move on to your second war.
Before doing either of these, browse as much of the enemy AI defenses as possible to see which looks better/more practical. Hopefully one of them will still work...
