Shimura Danzō's death had not been covered up. On the contrary, under Uzumaki Kuming's deliberate arrangements, news of Danzō's death was spread throughout Konoha.
Everyone knew that Danzō had been a hero of Konoha, killed in battle outside the village while protecting it. And before long, the killer was identified: Konoha officially declared that the ninja who had killed the hero Danzō had been from the Land of Grass. With Uzumaki Kuming deliberately fanning the flames, public opinion in Konoha quickly grew heated.
The rank-and-file ninja had no idea about all the twists and turns behind the scenes. They only knew that their village's hero had sacrificed himself to protect it. All they had to do was avenge him. That was all.
Then, at a Jonin meeting, Uzumaki Kuming overruled the objections and announced that Konoha would go to war against the Land of Grass. His mobilization order had barely gone out when, within just a few hours, a force of several thousand ninja had crossed the border and invaded the Land of Grass. The one leading them was Hatake Sakumo.
The speed of the invasion left the entire Shinobi World dumbfounded. By then, even someone thinking with their backside could tell that Uzumaki Kuming had clearly been planning all this for a long time.
The news of Konoha's attack on the Land of Grass had never even gone through the Daimyo, so the war began at breakneck speed. The Land of Grass was a small country, and its ninja forces were limited to begin with. At the time, the Land of Lightning and the Land of Earth were at war, so most of the Land of Grass's defenses were concentrated along its northern border.
They had not been particularly wary of Konoha, which had just suffered heavy losses in