No, it wasn't. We invaded a sovereign nation which posed little actual threat to the US. Saddam was the only thing holding this forsaken place together, and he was a known quantity. His actions could be reliably predicted.
Maliki is refusing to step down even though he lost the March elections. He is also in bed with Iran and the Sadrists. Allawi is basically a US puppet, but he has popular support of the population who are looking for a secular leader. Neither will be able to hold the various tribal regions together for long. They just aren't strong enough.
We are departing after 9+ years and leaving a fractured mess. There is no functioning central government, and neighboring countries are lining up to lay claim when we finally pull out.