I just wonder how much the 'lack of jumping capabilities' in the islands, as I understand Nathan's reply, does have an impact a) on the 'explosiveness' of the political situation on the one hand and b) on the gaming activities of the gamers.
Please don't get confused here. The Island powers have jump drive, they just never developed it on their own and received it rather late. The Islands were settled by STL generation ships and FTL in the form of jump drives came after most of the systems already were settled. That's a "designed-in" problem and that's why the Islands are a war waiting to happen.
Remember, the Islands were designed to be a wargame map
first and an RPG setting
second.
Briefly, the history of the cluster goes something like this. The European Space Agency launches 3 STL generation ships a few decades before Earth develops jump drives and meets the Vilani. Each ship carries a different linguistic/cultural groups; "English", "French", and "Germans". Around 4500 AD, the three ships arrive in the Islands Cluster and each colonizes it's own world. That's when the
fourth culture appears. A majority of the colonists were carried in cold sleep while multiple generations of the crews were born, lived, and died aboard the ships. The crews decide they don't want to settle a planet and prefer to keep exploring. They eventually colonize a fourth system, a planetoid belt, meaning four founding systems were settled.
Over the centuries, the old ESA STL ships travel around the Cluster and new STL ships are built too. Nearly all the other systems in the Cluster are settled by colonists picked up by those ships and dropped off at the other systems the ships have found. The four original worlds settle "daughter" worlds and those "daughters" settle further worlds. Of the four linguistic/cultural groups, the "French" settle the most worlds in the Cluster with their original world, Amondiage, settling daughter, granddaughter, and even great-granddaughter worlds.
The whole Cluster plods along linked by STL ships with schedules measured in years until the 3rd Frontier War when an Imperial navy cruiser misjumps into the Cluster. It limps into the planetoid belt I mentioned above, the one settled by ESA STL ship crews, and manages to repair it's jump drive with the help it gets there. After the cruiser jumps home, the Belt culture builds it's own jump drives thanks to what they learned and begins to create an empire.
Then the IISS shows up.
The IN cruiser reported on what had happened, the Imperium correctly deduces the Belt culture will reverse engineer jump drive, and the IISS is sent to "restore the balance of power" in the Cluster. The Scouts do this by picking seven likely worlds and giving them jump drive technology. The Belt culture's empire is stillborn and the Islands become the eight man wrestling match I wrote about earlier.
Obviously, that story has holes you can fly a
Tigress through. Among many other things, when you look at the history of the
OTU, the idea that a mid-rift cluster of over twenty worlds would remain out of contact for thousands of years is ludicrous. Whether you go by the original 6 parsec gap or the later 7 to 8 parsec retcon, anyone with jump3 or better and extra fuel tanks could visit the Islands any damn time they pleased.
What we need to remember is that the Islands were crafted as a wargame and, at first, only vaguely attached to the
OTU.
GDW basically said
"They're in the Great Rift... someplace..." pointing to some gray area on the map where only a few pencil marks appeared. The problems began when that gray area began to get colored in. You look at the maps now and the claim that the Islands were unknown until after the Third Frontier War will either make you laugh or gnash your teeth. Plenty of people, myself included, have come up with various excuses. None really work because the Islands were never really meant to be an integral part of the
OTU's story. They were a place you could fight a strategic wargame and little else.
Anyway, the canonical Islands is the eight-man wrestling match between paranoids I wrote about. The game they're playing is a zero sum one, any achievement by one power comes at the expense of another. It's set-up this way because - as I've constantly repeated - it's a wargame.
Each of the eight powers has one or more colonies/client states. Any attempt by one power to reduce one of the few remaining neutral worlds to colonial and/or client state status will mean war with another power or powers. And any war that breaks out between two or more powers will bring the others in too. The situation is like pre-WW1 Europe and deliberately show. All this means that any "finagling" your players get into will have consequences all out of proportion. Each of the eight powers is closely watching the others and closely watching whatever goes on anywhere in the Cluster. There isn't a lot of wiggle room for the type of campaign you've mentioned.
You're going to need to defang the Cluster. I always thought that preventing the secondary/tertiary colonization of the Cluster until after the IISS hands out jump drive might do the trick. This means only Amondiage, Neubayern, and New Home in the Old Islands subsector are settled along with Serendip Belt in the New Islands subsector. None of the subsequent STL colonization that "filled" Cluster occurs. When the Imperium hands out jump drive technology, a colonization rush does begin but it's more like the one seen in
2300AD where one power cannot lay claim to entire system and many systems host colonies from multiple powers. Run the clock forward a few centuries and you've got a nicely jumbled collection of colonies, ex-colonies, old powers, new powers, and everything in between with lots of wiggle room for all sorts of finagling.
Of course, whether my gibberish is of any help is debatable. I'm quite sure you'll quickly come up with ideas that will work for your RPG group.
Good luck.