From Wiki—
False flag operations
False flag operations are covert operations conducted by governments, corporations, or other organizations, which are designed to appear as if they are being carried out by other entities. Numerous conspiracy theories have developed suggesting that false flag operations have been carried out throughout the 20th century, and the secrecy of the true nature of the events have been maintained by successful cover-ups. The following are some attacks that are believed by some to be examples of false flag attacks:
The Great Fire of Rome was blamed on early Christians, but many people both then and now believed that Emperor Nero deliberately set the fires to make room for his palace that was subsequently built in the area.
On February 27, 1933, the German parliament, the Reichstag building, was subject to an arson attack; this is seen as the pivotal event for the appropriation of authoritarian power by the government of Nazi Germany. Several leading German historians concluded that the fire was a secret Nazi operation for which the Nazis then blamed a communist.[7] “Along with Communist propagandists, serious scholars have been ranged on the side of the proponents of the Nazi conspiracy theory”[8]
Another False Flag Operation:
http://en.wikipedia.org/wiki/Sergey_Kirov
Stalin had him killed so that he could justify the slaughter of what would become millions of people.