Intergalactic Alliance - A Galaxy of War

Terra (Earth) has been united. It seeks to expand into the universe but soon realised that the galaxy was filled with war. On the brink of defeat, Terra reached out to a young but powerful marine for help. Soon the galaxy created the largest alliance in known history. However, peace never lasts. The True Light order threaten to return things to how they were and stop the Intergalactic Alliance from bringing Terran rule over the galaxy. Will they succeed in doing so or will the young marine use his power to protect the IA?