Marching to the land of Spade Kingdom was a large troop raising the flags of the Karo Kingdom. Those who had a glimpse of this large troop spread awareness to the neighboring kingdom. Since the establishment of the said land, there was never a time they had seen the Karo Kingdom wage war with any kingdom.
There were disputes and political tensions, but the people of Karo, especially the rulers in the said land were rational. They weren't fond of settling any disputes through bloodshed but always find a peaceful resolution and compromise.
For the Karo Kingdom to resort to war, the Spade Kingdom had surely crossed the line no one should. Therefore, those lands close to the Spade Kingdom had either closed their borders or deployed soldiers in case the war would reach their lands.