The lie?
I guess if you want to keep it down to basics, no personal opinions permitted, WMD's in Iraq is the lie, since they weren't found and you cannot substantiate your claims. In a court of law, your case would be thrown out for lack of proof. You have some circumstantial evidence but not enough to prove beyond reasonable doubt that they existed and were in Iraq at the time of your invasion.
You can answer, "We will find Them".......but that is only an opinion, it doesn't prove they exist.
So in essence, and from a legal standpoint, your actions are likened to filing a false report resulting in an illegal search warrant.
Yes, so far, your president has lied.