I'll also give my own rundown:
In a far future, hundreds of years or so, a superpower (USA or some futurized variant) brings the world under its rule and creates a system of orbital satellites with the power to destroy all ICBM's and nukes of the like as well as wreak destruction to any place on the world on-par with nuclear weaponry. The key to this Orbital Eyes system is lost.
Dragnov Federation and Legium Republic are two countries. They were originally (presumably a long time ago) together and part of a single larger country, the kingdom of Loomis.
Dragnov, under the pretense of reuniting the two countries, waged war on Legium.
The first chapter signals the end of that gruesome war, where Dragnov pushed all the way to the capital of Legium and unleashed a low-altitude, ground-hugging warhead that blew up an area near the capital. Legium officially surrenders in response.
-In between these events, Legium's elite team of Jackals had an incident where their captain Genocide/Grahalt Mills is framed for war crimes by the rest of the group's members, as organized by Krayz.
Meanwhile, the Legium administration/higher-ups officially surrendered, but a sizeable portion of the Legium army, Legium 3rd army (later known as Legium People's Army), had not given up and didn't recognize surrender. They retreated in the cover of mountains to rebuild their strength.
Dragnov continues to try and quell uprisings and takes the Legium Republic's forces under their command.
-Mills breaks out and wages his own war, taking out comrades, gaining comrades, losing them, etc. Eventually, teaming up with Legium People's Army.
Legium People's Army mounts an operation to retake the capital of Legium, taking advantage of a rising Resistance to Dragnov rule by the people of Legium.
-Krayz, after taking down Mills, rises in rank as part of the Legium Republic that is part of the Dragnov Federation. However, he secretly owes his allegiance to the Kingdom of Loomis, being part of a secret organization known as Divan, made up of Loomis nobles. But even more secretly (the ultimate quad agent), he has his own elite army as the true royal successor to Loomis, with a plan to take over the entire world using the power of the Orbital Eyes. He operates under the pretense of weakening both Legium and Dragnov, killing off Dragnov officials to loosen their grip over Legium and have them destroy each other more.
-Taking advantage of the Resistance also comes Criville, the leader of Volks Keil, previously from a far-right nationalist party of Legium, Legtos People's Front. He embodies the heart of the people of Legium and intends to weed out the corruption of Legium's higher-ups.
As the uprising continues, parts of Dragnov-owned Legium Republic forces defect over to the Resistance. Volks Keil mounts its own assault to assist the Resistance. People's Army also commences its operation. Ex/forcibly retired soldiers join the fray. UItimately, every faction there is ends up fighting against Dragnov in this uprising.
This chapter finally finishes what the uprising started in retaking the capital, but also begins the real conflict as everything is falling into place as Krayz wants with Legium and Dragnov starting to wage war once again.