that can't be invaded.
That is the key phrase. Name me any other faction with the ability to warp time and space and make themselves impossible to be invaded. Sure, the Republic's fortress is not very big, but honestly, does it have to be? Ask yourself. What would you rather have: Fourty worlds that cannot be invaded by any means, or 400 worlds that can be invaded. I would rather have the fourty, because that would be fourty worlds that are perfectly safe, that I can build a powerful and extensive industry, R&D facilities, and economy within without the enemy being able to breach its defenses. This gives me the necessary power and economy to raid my enemy's facilities and invade their worlds, expanding my powerbase while my enemy can do -nothing- to strike back at me. Infact, if the ending of Surrender your Dreams is followed, this is -exactly- what the Republic does in the future... and it is going to suck when the successor states and clans that possess territory around Terra are going to get attacked and rolled by an enemy they cannot fight back against because the writers saw fit to give the Republic a superweapon that can only be countered by deus ex machina.
This is why the Republic is still a first rate power. Despite all their losses against the Successor States and Clans, those losses are irrellevant because the Republic possesses a superweapon that inevitably reverses the tables.
The Cappies seem to be the only power that hasn't collapsed in on itself, yet.
Well, The Combine collapsed on itself during the Jihad and the Black Dragons/Warlords has pretty much stopped them from making any progress in recovery. With insult to injury, it looks like the Black Dragons have actually succeeded in a coup de tat, which very likely will mean a civil war as the Warlord of New Samarkand will move to crush his opponents and unify the Combine under his leadership.
The Federated Suns has been pretty stable during and after the Jihad. They have their rogue nobles, but mostly the rogue nobles attack enemy states, not eachother. Their biggest weakness is Caleb, but while things are almost inevitably bound for the pooper for them because of Caleb, it has not reached that point just yet.
The Lyrans were actually doing really well until their latest leaders made some collossal mistakes that handed their realm to the Wolves and Falcons on a silver platter. They are really in a bad spot, and I think things are so volatile in that region that almost anything could happen.
The Free Worlds League is probably the most intriguing. They are quite officially the Battletech chew toy, they spent a chunk of their history being irrellevant (3025-3036), another chunk being a Blakist/Comstar catspaw (3036-3069), and the remaining chunk of it dead (3069-3139). So I think their ascendancy is a bit overdue. Despite being attacked by the Wolves and Lyrans the Free Worlds League had managed to stay together, and have been slowly regathering most of the component states back together. Despite their ascendancy, though, they still have a long way to go before they can be considered a first-rate or even second-rate power.
