There's an old saying, "if you want peace, prepare for war." It is attributed to an ancient Roman author, though the concept easily predates him.
According to Sun Tzu, War is the Art of Deception. The Trojan Horse of ancient Greek Mythology was delivered under the banner of peace, but was a deception which led to the destruction of the city of Troy. We would do well to remain vigilant and prepared for a fight, especially if we desire peace, because others who desire to see us destroyed will see any disarming of our defenses as an opportunity. This holds as true for individuals as it does for nations.