Force Subs - BT Star League Invasions

[Balrog]

The time period is about the same as when the Periphery uprising and Civil War begins, however things have changed. The bastard Amaris, instead of weaseling his way into the friendship of the young First Lord, had a nasty accident some years ago whereby he slipped on a wet spot in his bathroom and cracked his head open on the toilet seat. The leader of the Star League instead becomes best buddies with General Kerensky, and the Star League is currently enjoying peace and stability. Until, of course, a little outside context problem happens, which in this case is separated into a number of individual scenarios. Assume for all that the invasions begin in the Periphery, several dozen lightyears from League borders, around the same area the Clans came though during their invasion, for simplicity's sake.

First scenario, the Zerg Swarm from Starcraft appears over some backwater world several dozen lightyears deep in the Periphery, and it is very confused. The Overmind had opened what he thought was a warp portal to the Protoss homeworld of Aiur, only instead to find himself and the entire Swarm (or at least as much as he took with him during the original invasion) over another human world. Pissed off he lost his prize Kerrigan and figuring he'd make lemonade out of lemons, he decides to assimilate more humans and build a truly titanic force before making another go at the Protoss. Discovering that he is still able to create warp portals in this area of space, he decides to go on an eating spree and gobble up all the humans in the League, before heading back to face off again with the Protoss.

Second scenario, an exploration expedition makes contact with a strange fish-shaped ship in the Periphery, and through a tragic series of events begins a shooting match with it before the damaged mystery ship withdraws. Turns out the Minbari didn't like having their leader Dukat killed, and immediately being their war of genocide on the humans. The other Babylon 5 powers are also around, although obviously their territories has been moved to make room for a much larger empire of humans, and just like before they'll want to sit this one out, at least for now. The Vorlons, sensing someone's screwed around with time and space, will show a little more caution before making their (admittedly rather weak) attempt to intervene and save the humans, and suspecting the Shadows of causing the disruption they will be more active in preventing their making an alliance with the Star League.

Third scenario, a peaceful unimportant Periphery world is discovered, upon the arrival of a route Navy patrol, to have been bombarded from orbit in a most horrifying way. And the strange silvery ships who caused this destruction are still around. The Covenant from Halo have discovered humanity, and their gods have called out for its destruction. Sensing that there might be Forerunner artifacts on some of these human worlds, they will show the same due caution they did in their own universe. However, there are no Halos or stupid Flood, since this time the Forerunners weren't fucking idiots and took care of the problem in a timely fashion, before deciding to leave the galaxy for greener pastures.

The final scenario, another exploration expedition makes contact with a strange device deep in the Periphery, and somehow find a means of activating it. Unfortunately, shortly after, the device allows a fleet of alien ships to jump in, and they proceed to flip out and kill the humans. The Turians are in a rather militant mood concerning species activating these Mass Effect devices, and declare war on the Star League. The other Council races decide to go along with this for now. Sovereign has caught a nasty computer virus while he was looking up tentacle porn, and so the Reapers are going to be sitting this one out.

Star League's goal in all these scenarios is, obviously, survival. Whether that means complete destruction of their enemy, some type of negotiated peace, or whatever is irrelevant.

[Batman]

In space the Minbari would have a field day regarding combat. EarthForce was getting slaughtered and they at least had roughly comparable firepower and strategic mobility. The Inner Sphere barely has warships to begin with, vastly inferior tactical and strategic mobility, vastly inferior firepower (B5 YR weapons are KT/s-Inner Sphere, not so much), and very probably has to deal with Minbari Stealth systems.
The interesting part would be ground battles, which the Minbari, for some arcane reason, at least occasionally decided to wage, because we don't know beans about the Bonehead surface forces (that I remember at any rate).
If the Minbari decide to keep this in space, unless the Vorlons step in (or humanity manages to establish a dialogue that isn't sabotaged by the Centauri at the behest of the Shadows), the Star League is done for.

[Chris OFarrell]

Uh I think you are confusing the 3025 era Battletech with the 2075 one.

In short, at this point in time the Inner Sphere has tens of thousands of warships, an intact technology base and so on...

[Batman]

You know, I rather think I was, though I think you meant 2750, not 2075

[PainRack]

The Inner Sphere as a whole is simply not orientated to fight a war against any other major space power. Yeah, the Star League had warships in the thousands, but the fact still remains that her FTL take weeks, FTL comms take hours to days at best, to weeks for "normal" messages and her military is severely undermanned. It gets relatively worse here.
While the Star League was able to deploy more armies to fight wars, due to the limitation on private House forces, her armies are still way too small for any real defence. Any space power which has faster FTL, and virtually all of the powers mentioned here has that, the IS is screwed.