So, I've come across a fair amount of confusion concerning astrogation, the Treaty of Coruscant, and recent history. Because of this, I've decided to do a short write-up (with pictures!) of the changes in galactic politics since the rise of the new Sith Empire. This is the best I've been able to trow together, based on available lore.
I. Labels
To make this easy, I'm using the galaxy map from in-game. As you can see, I've marked the planets that are there in-game, the two factions fleets, Csilla, and Kwenn. I tried to get the locations of the planets right, but I'm sure they're a little off. I've already been informed that Csilla is not far enough west, please don't shoot me my Chiss friends. The important thing is that it's on the same side of the galaxy as the Empire and away from Republic influence. Also, apologizing now, I do not have Rise of the Hutt Cartel, so information concerning Makeb may be incorrect.
A note on color: Blue is Republic, Red is Empire, Yellow is Hutt, Green is Independant.
II. Before 30 BTC
This map is before the Great Galactic War. The Empire is expanding west from Dromund Kaas, at some time encountering the Chiss Acendancy. Voss is undiscovered. The Republic is in a period of growth and expansion, and it's influence is felt even in the Outer Rim. Belsavis is made into a prison shortly before Great Galactic War begins, with it's own dedicated garrison.
III. Great Galactic War
The Great Galactic War open as the Empire advances down the Tengel Arm, shown by the small arrow in the Seat of the Empire. As the Republic scrambles to reposition it's military, the Senate falls into chaos as worlds are prioritized. Many systems leave. This is shown by the Blue arrows to the Core Worlds from the west.
While the Republic is off-balance, the Empire advances through the Outer Rim, almost unchecked. The Republic manages to cripple their fleet at the Battle of Hoth, but the Empire has already established bases on several Rim worlds. Note that The Empire does not yet know the location of Belsavis.
The primary Imperial assault comes through the corridor near Hutt Space, before stalling at the sieges of Bothawui and Balmorra. After the failure of the Mandolorian Blockade, the Empire goes on the offensive again, hitting, but unable to hold the Core Worlds including Alderaan. The final, and most well known move of the War is the Sacking of Coruscant.
Also of note: At some point during the war, Manaan is bombed by the Sith and the Selkath abandon the surface and galactic politics/trade. As such, Manaan is no longer exporting kolto.
IV. Treaty of Coruscant
Based on how the Treaty is described, I'm using
http://en.wikipedia.org/wiki/Treaty_of_Tordesillas as model.
Planets visited in-game during this period: Tython, Ord Mantell, Korriban, Hutta, Dromund Kaas, Coruscant, pub!Taris, imp!Balmorra, Nar Shaddaa, Tatooine, Alderaan.
By the terms of the Treaty of Coruscant, all space south of the white line is Republic space, all space north of the line is Imperial Space. Note that Alderaan is independant, but in Republic space since they seceded
after the Treaty was signed. The Hutt Cartel managed to either ignore the Treaty or be written out of it, allowing movement of either faction through their space. Diplomatic vessels are allowed to cross the Treaty Line, but they are watched closely. Smugglers and other fringers travel through uninhabited systems and Hutt Space to move between the factions.
The Republic during this period focuses on regaining the support of the mid rim systems that became disillusioned during the war. Alderaan secedes just after the Treaty is signed.
Note that though The Treaty divides Imperial and Republic Space, The respective factions do not actually control the entirety of their regions. This is further complicated by the Imperial Outer Rim bases that the Republic does not have knowledge of or the resources to root out.
Imperial operations in the Outer Rim are technically in violation of the Treaty Of Coruscant, but the Republic does not have a firm enough grasp of the territory to stop said operations. That said, should the Republic fight against the Imperial operations there, they would
not be in violation of the Treaty.
Belsavis is an exception. It is unclear just how strong the garrison is, but it is strong enough to prevent smugglers from landing (source: One of the Republic quests on Belsavis).
Voss is discovered during this period, and the Empire attempts to invade. Though the Republic offers to assist, almost reigniting the War, the Voss are able to fight off the Empire on their own.
Tython is rediscovered shortly after the Treaty is signed.
V. Open War
Planets visited in-game during this period: Makeb, Ilum, Corellia, Voss, Belsavis.
Guess what? Just to make things more difficult, for some classes Act II is war, for some it is not. THANKS BIOWARE.
Might be during this period, might not be: Hoth, Quesh, imp!Taris, pub!Balmorra
In order to explain the Act II war/peace problem, I am thinking the Empire starts openly ignoring the Treaty. The Republic begins reacting before the Declaration of War clears the Senate.
ANYWAYS. The opening moves of the new war are the Imperial invasion of Taris and the Republic liberation of Balmorra. At the same time the Imperial bases in the Outer Rim are reinforced and begin fighting Republic forces on Hoth and Belsavis.
Both the Republic and the Empire increase the scale of their diplomatic missions to Voss.
The Empire's first major move in the war is the invasion of Corellia, which is countered shortly after by the Republic. The Empire then discovers and attacks Ilum.
Both sides experience tension with the Hutt Cartel on Quesh, and then even more so after the Hutt Cartel begins to expand by attacking Makeb.
Sources:
http://www.swtor.com/holonet/galactic-history,
http://www.swtor.com/holonet/planets/, Jedi Knight story to 50, Consular story to 50, Imperial Agent story to Act II, Smuggler story to Act II, Wookiepedia.
[ADMIN EDIT: Added spoilers tag to title. You are warned!]
