Repeated on-stage jabs at former Vice President Joe Biden from former US housing secretary Julián Castro at Thursday night’s Democratic debate, paired with a bizarre and vaguely offensive Biden monologue about record players in response to a question about on race, made the question of Biden’s mental fitness for office impossible to ignore.

It’s an awkward topic that can easily verge into outright ageism. But Biden sounds sloppier and less put together than the other two frontrunners from his age bracket, Sens. Bernie Sanders (78) and Elizabeth Warren (70). He’s always been gaffe-prone, to be sure, but something about it feels worse now to a lot of Democratic voters.

The Castro attack — “Are you forgetting what you said two minutes ago?” — and the “record player” answer got the most attention. (Castro denied he was talking about Biden’s age.) But another Biden moment also raised red flags: His response to a question about the Obama administration’s withdrawal from Iraq.

Biden played a role in implementing the withdrawal, and thus should be able to speak knowledgeably about it. But his answer, which discussed both Iraq and the war in Afghanistan, made very little sense overall.

Foreign policy is supposed to be one of Biden’s clear areas of competence, a policy area he’s focused on throughout his career. The fact that he stumbled so badly should raise serious questions about his presidential bid.

Biden’s Iraq jumble

The question began when ABC’s David Muir asked Biden: “Was it wrong to pull out of Iraq that quickly? And did the move actually help ISIS take hold?”

It’s a misleading question — Obama’s approach to withdrawal was not the reason for ISIS’s rise — and should have allowed Biden to go on offense, defending the last president’s record on an important foreign policy issue.

But that’s not what happened. After asserting that the withdrawal wasn’t a mistake, Biden instead talked for a bit about his support for the initial invasion of Iraq back in the Bush administration. This seems like a reference to a recent controversy about Biden falsely saying he opposed the invasion “immediately,” but that wasn’t brought up Muir nor clearly explained by Biden:

With regard to — with regard to Iraq, the fact of the matter is that, you know, I should have never voted to give Bush the authority to go in and do what he said he was going to do. The AUMF was designed, he said, to go in and get the Security Council to vote 15-0 to allow inspectors to go in to determine whether or not anything was being done with chemical weapons or nuclear weapons. And when that happened, he went ahead and went anyway without any of that proof. I said something that was not meant the way I said it. I said — from that point on — what I was argued against in the beginning, once he started to put the troops in, was that in fact we were doing it the wrong way; there was no plan; we should not be engaged; we didn’t have the people with us; we didn’t have our — we didn’t have allies with us, et cetera.

The answer itself is confusing, obscuring the fact that he spent at least a year defending the decision to invade Iraq before he turned on the war.

Things get weirder when Biden gets to the actual meat of the question, about whether the Obama Iraq withdrawal was a mistake. He offered two short paragraphs — one recounting his role running Iraq policy under Obama, and a second that frankly makes no sense:

It was later, when we came into office, that Barack turned — the president turned to me and said, ‘Joe’ — when they said we’ve got a plan to get out, he turned to the whole security and said, ‘Joe will organize this. Get the troops home.’ My son spent a year in Iraq, and I understand. It made — and we were right to get the combat troops out. The big mistake that was made, which we predicted, was that you would not have a circumstance where the Shia and the Kurds would work together to keep ISIS from coming — from moving in.

I’ve spent a while pondering this last line — “the big mistake that was made, which we predicted, was that you would not have a circumstance where the Shia and Kurds would work together to keep ISIS from coming” — and I can’t make heads or tails of it.

The Shia majority and ethnic Kurdish minority are ISIS’s bitter enemies, given that ISIS is a Sunni jihadist group. I think Biden is trying to say that they should have cooperated on counter-ISIS efforts between 2011 and 2014, but didn’t. But lack of Kurdish-Shia coordination isn’t really what led to the rise of ISIS in Iraq (there were a lot of other causes).

Moreover, Biden’s answer suggests that someone other than the Kurds and Shia made a “big mistake” in judgment. I’m having a hard time understanding the substance of the supposed mistake, who in particular made it, what the consequences were, or why, if it “we” (presumably the Obama administration) predicted it, that it wasn’t stopped.

The overall impression was of Biden just saying some Iraq-related things that either didn’t address the question or were literally incoherent. And this is a policy area he specialized in, both during his time in the Senate during the Bush administration and as Obama’s vice president.

Biden’s Afghanistan jumble

But Biden’s answer to Muir’s question wasn’t just about Iraq. He wanted to talk about Afghanistan policy, a major issue on the debate stage, and so redirected some of his time to that particular issue.

Candidates change the subject during debates all the time. But the substance of what Biden said about Afghanistan was kind of confusing. Here’s the first half:

I’ve been in and out of Afghanistan, not with a gun, and I admire my friend [Pete Buttigieg] for his service. But I’ve been out of Afghanistan I think more than anybody on this — and it’s an open secret, you reported a long time ago, George, that I was opposed to the surge in Afghanistan. The whole purpose of going to Afghanistan was to not have a counterinsurgency, meaning that we’re going to put that country together. It cannot be put together. Let me say it again. It will not be put together. It’s three different countries. Pakistan owns the three counties — the three provinces in the east. They’re not any part of -- the Haqqanis run it. I will go on and on.

This answer struck me as a bit strange. Not just verbally, in terms of shifting between “countries” and “counties” and “provinces,” but substantively — the idea that Afghanistan is actually three distinct countries that cannot be meaningfully united.

Afghanistan does have three major geographic regions, but it’s not clear how politically important those geographic distinctions are. My impression was not very — there are not major separatist impulses in Afghanistan divided by geographic region — but I’m not an expert.

So I turned to someone who is: Steve Saideman, the Paterson chair of international affairs at Carleton University and the author of two books on the war in Afghanistan. He was as befuddled as I was.

“When talking about Afghanistan and reaching an agreement, I have never heard anyone refer to three regions,” Saideman told me. “While federalism will probably play a role, the numbers there are around 30 or so for all of the provinces, not three.”

It’s possible Biden instead mixed up two countries: “Biden might have confused Afghanistan with Iraq,” Saideman suggested.

In the 2000s, Biden proposed a plan for splitting Iraq up into three distinct federal regions along ethno-religious lines — semi-autonomous Sunni, Shia, and Kurdish regions. This is not a very good idea, and it didn’t catch on with Iraqis. But least it tracked with the politically salient sectarian divisions in the country, which it doesn’t with Afghanistan.

The second half of Biden’s answer was perfectly cogent, aside from a questionably feasible proposal to force Pakistan to accept US troop basing in its borders. Biden is arguing that the US needs to cut down its troop presence and focus more narrowly on fighting potential terrorist threats to the US homeland rather than the overall Taliban insurgency — a defensible position that, as Biden’s notes, he’s been advocating since the Obama administration:

But here’s the point. The point is that it’s a counterterrorism strategy. We can prevent the United States from being the victim of terror coming out of Afghanistan by providing for bases — insist the Pakistanis provide bases for us to air lift from and to move against what we know. We don’t need those troops there. I would bring them home. And [Joint Chiefs Chair] Joe Dunford’s a fine guy, but this has been an internal argument we’ve had for eight years.

But the “three countries” gibberish overshadowed the more sensible part of the answer. Why is Biden seemingly porting over dubious concepts from Iraq to another conflict entirely? Why were major portions of his answers on both Iraq and Afghanistan so deeply flawed? Why did he perform so poorly in this area of alleged competence?

These are worrying questions, and ones that even Democratic-leaning experts are starting to ask: “If Warren gave Biden’s answer on Afghanistan, she would be eviscerated,” Max Bergmann, former State Department official and a senior fellow at the center-left Center for American Progress, tweeted during the debate.

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