Politico takes this as the strongest sign yet, among many signs being sent today, that big Mac is headed for the exit. It’s a nasty dilemma for Obama, but the calculus is straightforward: Which will cost him more, looking weak by retaining McChrystal after his staff’s shots at Biden, Eikenberry, etc., or shuffling the command in Afghanistan at a delicate moment? Via Danger Room, the case for giving him a second chance — sort of:

Not only is McChrystal the “only one with any sort of relationship with [Afghan president Hamid] Karzai,” says this civilian advisor to the McChrystal-led International Security Assistance Force. Eikenberry “has no plan, didn’t get COIN [counterinsurgency] when he was the commander and still doesn’t.” Plus, the advisor adds: “The Embassy hates Eik. That’s not necessarily an indictment (I’m no fan of the Embassy). But it contributes to the dysfunction and it means that half the Embassy is focused on keeping Eik in line.”

But even this McChrystal backer admits that the backbiting and the sh*t-talking between the general’s camp and Eikenberry’s is hurting the war effort.

“There are very few things we control in Afghanistan. In every review of COIN best practices, ‘unity of effort’ tops the list. Every. Single, Review. And we’re totally f***ing it up; f***ing up the one thing that should be in our control,” the advisor says. “We can’t control Karzai, or the ANP [Afghan National Police], or the Pakistani tribes, but we should be able to get our sh*t in one sock and we’re not.”

Indeed, Karzai issued a statement of support for McChrystal this morning. Case closed, then — he’s staying on, right? Not so fast. Also via Danger Room, has big Mac become more of a liability than an asset?

If President Obama fires McChrystal, there’s a very real possibility of months of chaos as the commands switch over—just as there was last year, when McKiernan was axed. Worse still, it’s unclear that McChrystal’s original strategy can be pulled off without his staff there to push it down the chain of command. There’s also another possibility, namely that Team Obama could use this as an opportunity for reversing many of McChrystal’s astoundingly bad decisions (like going into Kandahar in the first place), focusing resources instead on winnable battlegrounds like Kunduz and Herat and Khost.

Reportedly names of replacements are already being kicked around the Pentagon, with Gen. Mattis and possibly Petraeus himself targeted as successors. For my money, the worst detail in the “Rolling Stone” piece was an aide claiming McChrystal told people that Obama appeared “intimidated” by military brass during an early meeting after his inauguration. However true that may be, it’s the last thing a commander should want troops in the field believing about a C-in-C who’s sending them into combat, especially given the preexisting stereotype of Democrats being “wimpy” on war. It’s poisonous to morale, and would be unimaginable coming from someone like Petraeus. But then, as one of Byron York’s sources tells him, McChrystal’s tactless disdain for his civilian superiors is apparently well known. Provided that replacing him wouldn’t instantly wreck the whole mission — which isn’t exactly rolling along anyway — I’d fire him.

Just as I’m writing this, I’m seeing reports that Joe Klein told Rick Sanchez on CNN that McChrystal’s submitted his resignation. But Marc Ambinder, who’s tapped into the White House like few other bloggers are, is hearing that the war cabinet is urging Obama to keep him on. Maybe Dan Foster is right: By having McChrystal submit his resignation but refusing to accept it, Obama gets to save face while also retaining him in the field. Stay tuned; supposedly The One’s going to speak sometime soon.

Update: Via the Right Scoop, here’s the CNN report on Joe Klein’s scoop about McChrystal’s resignation. No independent confirmation yet, although it’s possible that Klein’s source is McChrystal himself. He’s a big fan of Mac, despite the fact that he argued today at Time’s website that McChrystal should go.

Update: Time is now walking back Klein’s scoop a bit, claiming that McChrystal didn’t actually tender his resignation but offered to do so. Over to you, Barry.

Update: The plot thickens: Toby Harnden of the Telegraph says a source tells him that McChrystal has indeed tendered his resignation and that the White House is “actively discussing a replacement” in case Obama accepts it.