In a dream which taught the evil of absolute power, Shifu gave Daniel a vision of an alien defense system designed to be deployed in a satellite network orbiting Earth. The AG-3 defense system could detect approaching Goa'uld ships thousands of light years away, and the weapons system could penetrate Goa'uld shield technology and destroy motherships. The system was powered by heavy liquid naquadah fuel cells. In his dream, Daniel provided the knowledge to build the weapons system, and he had complete control over its deployment, however the proliferation of weapons had disastrous consequences when Daniel launched an attack that annihilated Moscow in seconds. Daniel did not retain the knowledge of the dream, and the system was never actually built.
Cross Reference: Paul Davis, Shifu, General Vidrine
Episode Reference: Absolute Power