The UNDF has a big problem, not the Tarbotians or Clones or another enemy power, but with an ageing fleet. During the first decade of the 2100s, the DDS (as it then was) fleet expanded greatly. The problem for DF is that the major ship classes built then will reach the ends of their lives in the 2130s.
The money which funded the fleet expansion, at first a war budget from the UNP and then augmented by billions of zarks in land and weapon sales, is no longer there.
The key problem is with the Quasar, Isometric and Provider/Extender fleets. These will reach the ends of their service lives from the early 2130s onwards. DF simply cannot afford (or even has the industrial capacity anymore) to replace all three at the same time.
DF have indicated they will not replace the Quasar fleet, relying instead on the Warrior fleet and LRM force for strategic attack. The Missileers are likely to be rebuilt as transports and oilers, this will help delay the need to build brand new transports.
The big question remains with the Isometric fleet. DF are hoping the forthcoming Advanced Rome is a success, as they plan to use this design as the basis of an Isometric replacement. The alternative will be to completely rebuild the Type 41 though this will be more expensive in the long run.
DF have just begun a full review of their fleet, this will help guide them with some difficult decisions to come.