War is Peace refers to to the fact that while a country is at war, it can get away with murder on the home front, on the pretext of "rooting out traitors." A good example of this is the Espionage Act passed by Congress and signed by Woodrow Wilson in 1917, which had little to do with spies, and a lot to do with allowing the feds to round up anyone who criticized the Government's actions during a war. (Fun trivia fact: Since the United States has officially been in a state of emergency since the Korean War, the Act is still in force).
Ignorance is Power means that as long as you believe what you are told, the state has the power to justify whatever it wants. Example: in 1998, Clinton ordered tomahawk missles to be fired at a Sudanese Pharmaceutical plant. His rationale was that it was being used to construct bio-weapons. Six months later, the government quietly admitted that it had no conclusive evidence of this.