Here is a campaign I have in mind (largely borrowed from the Legend of Galactic Heroes)
Characters:
Alpha 1 is a new recruit in the 70th blue lions. He doesn't talk much, but he gets the job done.
Alpha 2 is the wing leader. He is the serious type. Though still young, he is seasoned and does things by the number.
Alpha 3 is a young lady. Daughter of an Admiral. She defied her father by joining the fleet. A talented pilot, but a little spoiled.
Alpha 4 is a young guy. He is the hot shot of the group. Womanizer. Constantly causing troubles. He also despises Vasudans.
Act 1: Evacuation of Capella.
Hundreds of refugee ships were flooding into the Vega system. Chaos everywhere. Pirates were flourishing. Some Shivan ships also managed to jump into Vega.
Act 2: The Vega incident.
Unable to find adequate accommodations in Vega, the refugees started to migrate into other systems. Worried about a large influx of Terran population, the governor of Deneb, Prince Abdula, ordered an blockade of the Vega Deneb jump node. Sentry guns were set up and 13th Vasudan Battle Group kept the refugee group outside the node. Frustrated, one of the refugee ship forced its way into the node, but was destroyed by the sentry guns before it could make the jump. Things got out of control. Refugee ships opened fire against Vasudan warships and in the ensuing firefight, 7 refugee ships along with 1 Vasudan cruiser were destroyed. Terran politicians were outraged, yet the Vasudans in the security council refused to open an investigation. In protest, Vega withdrew from the GTVA. The security council declared martial law in Vega and ordered the 4th fleet to take control.
Act3: The second NTF rebellion.
The 4th fleet is having trouble putting out the resistance in Vega whereas Petrarch tries his best to keep the Vasudan 13th battlegroup out of this. A refugee ship filled with bombs rammed the Vasudan blockade, decimated much of the Vasudan fleet. Enraged, the 13th battlegroup moved all its mighty into Vega and attacked any suspected terrorists. During a standoff between the 4th fleet and the 13th battlegroup, a renegade Terran wing destroyed GVD Meru, killing the Visudan Crown Prince in the process. Admiral Petrarch was arrested for high treason and executed without a trial. The 4th Terran fleet, along with the 70th blue lions, defected to the rebellion. The 2nd and 5th fleet followed. More Terran systems declared independence from the GTVA. A new NTF was formed. The Vasudans suffered heavy losses in Vega and retreated back to Deneb.
Act4: The fall of the GTVA.
NTF battleships started to pour into Beta Aquitae. While still superior in numbers, the loyalist fleets were poorly led and suffered low morale. The NTF achieved victory after victory. After a bloody last stand, the GTVA capital fell. Most of the Vasudan fleet were devastated and withdrew back into their own systems. All Terran systems joined the newly established Galactic Terran Federation.
Act5: The bleeding universe.
Divisions started to appear within the GTF leadership. While the hawks wanted to start a second Terran Vasudan war, the prime minister would like to make peace and rebuild the economy. The Terran Fleet commander plotted an unsuccessful military coup and was executed for treason. The Prime minister then started to purge the ranks of the GTF fleets. Thousands were killed. He, himself, was assassinated before long. Civil war broke out. The original members of the alpha wing now belongs to different camps. In the last mission, can you pull trigger against your old friends?