Chip Somodevilla / Getty Images

ABC News’ Michael Falcone reports:

Even Rick Perry acknowledged that his brain freeze at last week’s presidential debate was embarrassing. But, Herman Cain’s interview with the Milwaukee Journal-Sentinel editorial board on Monday may have topped it.

A video posted by the newspaper shows Cain struggling through the answer to a straightforward question posed by one of the editors who asks: “So, you agree with President Obama on Libya, or not?”

“Ok, Libya,” Cain replies, followed by 10 seconds of silence that the presidential candidate fills by looking down at the table and fidgeting with a bottle of water.

Then Cain turns to the reporters, appearing to ask for their reassurance on two facts: “President Obama supported the uprising, correct? President Obama called for the removal of Gadhafi?” he says. “Just want to make sure we’re talking about the same thing before I say, ‘yes I agree, I know I didn’t agree.”

“I do not agree with the way he handled it for the following reason,” Cain continues, his eyes looking up as if searching for the point he’s trying to make. “No, that’s a different one,” he adds, followed by more silence.

He starts up again: “I gotta go back to — got all this stuff twirling around in my head.”

Then Cain asks the editors to re-state their original question: “Specifically, what are you asking me, did I agree or not disagree with on what?”

The editor repeats: “I was wondering if you would agree with what he did or if you would have responded differently? It’s an issue that’s come up since you’ve been running for office.”

Finally, after more than a minute of apparent confusion, Cain attempts his response once more:

“Here’s what I would have — I would have done a better job of determining who the opposition is, and I’m sure that our intelligence people have some of that information. Based upon who made up that opposition — ok — based upon who made up that opposition, might have caused me to make some different decisions about how we participated. Secondly, no, I did not agree with Gadhafi killing his citizens. Absolutely not. So something would have had to been — I would have supported many of the things they did in order to help stop that. It’s not a simple yes-no, because there are different pieces and I would have gone about assessing the situation differently, which might have caused us to end up in the same place. But where I think more could have been done was, what’s the nature of the opposition?”

Cain’s difficulty with the answer to a basic question about Libya underscores concerns over the depth of his knowledge on foreign policy — an issue that has not been his strong-suit during the primary race. Most recently, in an interview with the PBS “NewsHour,” Cain seemed unaware China’s nuclear weapons program.

The former Godfather’s Pizza CEO did little to convince critics that he has a detailed grasp of international affairs at Saturday night’s presidential debate in South Carolina, which focused those subjects. Before the debate, Cain’s campaign manager, Mark Block, told ABC News that the campaign’s spokesman, J.D. Gordon, also doubles as the candidate’s chief tutor on foreign policy.