Why did Athens and Sparta agree to 30 year peace treaty?

Athens and Sparta agreed to the 30-year peace treaty, known as the Nicias Treaty, in 421 BCE to end the ongoing conflicts of the Peloponnesian War. Both city-states recognized the mutual exhaustion and devastation caused by the war, which had strained their resources and populations. The treaty aimed to establish a period of stability and cooperation, allowing both sides to recover and consolidate their power. However, the peace was fragile and ultimately failed to prevent renewed hostilities.