Pelosi v. Panetta
It's obvious that either Leon Panetta, Obama's head of the CIA, or Nancy Pelosi, his party's Speaker of the House, has to go. No administration can tolerate a permanent, public civil war between two such high-ranking officials.
Especially when their disagreement stems not from issues of policy but from matters of veracity and credibility, the battle must end in one of their resignations. You cannot have the head of the nation's first line of defense against terrorism calling the Speaker of the House a liar and being attacked by her in turn.