"Question: Was someone official behind Armitage's efforts? "

From Novak:
"An accurate depiction of what Armitage actually said deepens the irony of his being my source. He was a foremost internal skeptic of the administration's war policy, and I had long opposed military intervention in Iraq. Zealous foes of George W. Bush transformed me, improbably, into the president's lapdog. But they cannot fit Armitage into the left-wing fantasy of a well-crafted White House conspiracy to destroy Joe and Valerie Wilson. The news that he, and not Karl Rove, was the leaker was devastating for the left."

That COULD have been investigated, but the focus was ONLY on Libby- NO effort was made to charge Armitage, so that would not come out.