The Chestnut war
When Rose, the new Melkar, was born, Nirnivians feared Ostark might somehow learn the news despite the isolation policy. It was believed that if Ostark ever found out, a new war might start. Eventually, President Tamar, the leader of Ostark at the time, did hear of the coming of a second Melkar. Dreading Nirnivia might try something foolish in order to protect her from a non-existent threat, he tried a risky gambit. Tamar sent troops through the neutral zone in spite of the treaty, though they weren't meant to invade Nirnivia or anything of the sort. Quite the contrary, the plan was to have them be discovered by N.I.S.D.A. The small squadron brandished white flags indicating they came in peace and constantly broadcasted a message indicating that, due to the special circumstances, Ostark felt an exception should be made to the isolation rule in order to deliver a message. N.I.S.D.A. agreed to listen, though they remained on their guard. The Ostarkirans explained they heard of the winged child, and that while they believed her to be a mutant rather than a prophet, they had no intention of restarting the hostility over religious matters. Ostark would respect Nirnivia's right to their faith and let them worship their Melkar in peace, as long as Nirnivia didn't use this so-called second coming as an effort to invade and convert Ostark. The Nirnivian council had no such intention, remembering the horror that kind of zealotry brought in the past. The crisis seemed averted, but in truth, it had merely been delayed.
In the year 2128 on the Nirnivian calendar, a tragedy occurred. A small contingency of Ostarkiran troops somehow managed to infiltrate Nirnivia through the neutral zone without being detected. Upon arrival, they attacked a civilian neighborhood. Despite their limited number and arsenal, they caused devastating damage and killed many before being killed themselves by N.I.S.D.A. Some people managed to capture footage of the attack, particularly the massacre that occurred in a place named Chestnut Park. Many children died there, and the resulting images flooded the media. The Nirnivians were appalled and demanded blood. The council had no choice: Ostark committed an act of war, and with no way to communicate easily, they'd have to act immediately. Any attempt at communicating as President Tamar did years ago would result in a delay that might prove fatal to them, and so they ordered N.I.S.D.A. to retaliate. Thus, began the Chestnut war.
An intense conflict ensued and both sides suffered. It didn't take long, however, for Ostark to have the advantage. They had a bigger army thanks to their large population and better equipment since, unlike N.I.S.D.A., their military had been funded generously. Still, Nirnivia fought well and won many battles, but they seemed poised to lose the war. Then, when all hope seemed long gone, a shining savior showed up, though he wasn't exactly welcomed.