Interesting.
The Jovian Republic will have a significant edge in colonization efficiency due to their faster ships.
If the Jovian Republic can exploit its lead in colonization enough, then I see it as greatly to their advantage to grudgingly concede the UNE the right to peaceful passage through the warp point inside Mars orbit. But to _not_ concede the right to peaceful passage themselves.
This has a number of positive results:
1) The UNE will build colony ships and freighters with its shipyards instead of warships. This is good because trying to match the UNE with warships could result in a resource crash for everybody involved, with insufficient transport to bring in enough minerals to sustain things.
2) For the UNE to be able to exploit the minerals of G1-183 they need to be at peace with the Republic. This is also good. Looking back into Earth history, in the peace treaties that ended England's various wars with continental powers, England would often cede the lucrative sugar colonies it captured in exchange for a return to pre-war conditions on the continent. England could easily seize those islands again in time of war, but in the meantime it prevented a continental power from achieving hegemony.
So the existence of a UNE colony in G1-183 gives something for the Jovian Republic to threaten to seize if the UNE presses them elsewhere.
3) By maintaining the inside Mars orbit warp point as an "open strait", 'generously' conceded by the Jovian Republic, the UNE has to devote significant resources to defending the colony. A colony that is very far away.
4) Strategicly, this changes UNE concerns from "How can we attack and conquer the Jovian Republic?" to "How can we defend what we have and demonstrate the economic superiority of our system in colonization?"
5) Wouldn't it be nice to make the UNE foot the bill for Terraforming G1-183's planets and _then_, if necessary, take the colony away from them? Lol. Or perhaps, to induce said colony to revolt and recognize and defend its independence.
I would also seek to limit UNE ships to no more than 130% of current size, and build Jovian Republic ships slightly faster. That hopefully eliminates the strategic concern of uparmored UNE ships, forcing them into a predictable and counterable ship design choice.
The Republic's thinking was basically as you outline above. Every unit of resources and credit that the UNE spends on exploring and exploiting extra-solar space is that much less that they spend on building a navy. Of course, in the long term, it means that they will grow stronger because of their out-system investments, but the Republic is more worried about the short term.
Also, the feeling in the Republic was that if they imposed an unreasonable peace on the UNE, such as denying them access to any warp points, it would just ensure the next war, which they might not win. It might be inevitable anyway, but why conciously make things worse?
As for the UNE ship designs, the Republic decided to make no requirements part of the peace treaty, as they would be difficult to enforce and would be a constant source of irritation.
The Republic knows that the first thing that the UNE is likely to do is to redesign its ships to be much faster, matching or exceeding Jovian designs. In fact, this belief has been borne out by observed UNE actions, where the first three DD class units launched after the war were immediately sent back to the yards for a presumed refit. Although the Republic cannot know the details of the refit, the smart money is on a drastic increase in speed.
The Republic Navy is currently unsure of how to react to this situation. A sizeable faction believes that while increasing their speed will make the UNE a more dangerous enemy, the RN's advantage in other areas will more than balance things, especially given the fact that the UNE designs will have to make some compromises to achieve the higher speeds with the tech that they have. Making things problematic for the RN is their limited shipyard capacity, which has not increased since 2112, while the UNE's has increased by 40% in the six years since the campaign began. Major overhauls to the fleet need to be planned in advance.
As you will see in the next update, the Republic has devoted the bulk of their shipyard capacity to increasing their civilian fleet of freighters and colony ships. This has helped them establish extra-solar colonies, but it also means that they have only been able to accomplish minor refits to their fleet.
Kurt