You asked for it, so here are my two euro cents.
With the new invasion putting the FWL in jeopardy, the Chancellor committed additional forces to the growing Andurien melee, during which the Capellan Confederation lost a number of former Hegemony worlds when they proved incapable of consolidating their hold in the region. Aligning themselves with Tikonov in 2820, these worlds began to build a new state centered on Tikonov under the auspice of heirs to the old Hegemony bureaucracy. Although this region lacked a major domestic military presence, the insurgent forces of these worlds made them competitive opponents to their distracted invaders.
Why is there a rebellion in Tikonov?
The Skye Rebellion began as the First Succession War came to a close and as many former Terran worlds, unhappy beneath the Steiner yoke or fearful of being captured by the Draconis Combine revolted, joining in with the already fractious Isle of Skye. These rebels were soon aided by Free Tikonov forces bloated with secret ComStar help.
If there is an internal rebellion, why would the Lyran Commonwealth invade the Free Worlds League?
Any leader with two cents of common sense would focus on the rebels.
Meanwhile, the Federated Suns – a nation badly mauled by the Draconis Combine – found itself vulnerable to its own upswing in domestic dissent as March Rulers attempted to consolidate and prepare for another looming invasion of their devastated territory. Not too soon, the Capellan and Draconis March Dukes began looking toward their own worlds to rule, rather than New Avalon.
Do you mean that the people from these Marchs were turning their eyes towards their own dukes rather than towards New Avalon?
When forces loyal to Prince Davion arrived in the March to halt the Duke Hasek’s drive into Liao space, open fighting erupted between the two sides. As a result, the Capellan March declared its independence from the Davion crown in 2829. AFFS units from loyal Marches began to pour into the area, and while Prince Davion believed a massive show of force would quickly squash resistance, the move fatally weakened significant portions of the Federated Suns’ border.
Wouldn't the loyalist forces outmatch the rebels enough to crush them ? This might be even truer as the Capellan March is still focusing on the invasion of the Confederation.
As a result, the people of Tamar easily repulsed the Archon’s half hearted attempt to reclaim the province in 2834.
Why half hearted?
For the next 187 years ComStar worked to restore communications to the Inner Sphere. When they were finished in 3025, the Great Houses were no more.
Exhausted States, rebellious Marches, no communications over nearly 200 years and economies facing major problems are good reasons for the increased fragmentation of the Inner Sphere.
It reminds me a bit of parts of Asimov's Foundation with the centre of the Empire still acting as if they were prosperous while the Periphery was falling into a barbarian age and independence.
