The Sub Quantum Unified Intrinsic field Device or S.Q.U.I.D. was an invention that Adrian Veidt's science team, in cooperation with Dr. Manhattan constructed at Rockefeller Military Research Center. Veidt advertised it as a non-repleteable energy source that would solve the world's problems and avert the crisis.
However the SQUID, when teleported to Karnak, would trigger massive explosions in the major cities of the world, leaving Dr. Manhattan's energy "trace". This made the world unite against Dr. Manhattan, who teleported to another planet.
The SQUID actually is the movie version of the squid-like alien monster of the graphic novel.