There is nothing new in a government lying to their people to start a war. Indeed because most people prefer living in peace to bloody and horrific death in war, any government that desires to initiate a war usually lies to their people to create the illusion that support for the war is the only possible choice they can make.
It is inescapable historical reality that leaders of nations will lie to their people to trick them into wars they otherwise would have refused. It is not "conspiracy theory" to suggest that leaders of nations lie to trick their people into wars. It is undeniable fact.
This brings us to the present case.
Read all of it. See also The American Mafia Wife Syndrome.