STEPHANOPOULOS: And then the question is, how long does that go? A couple of days? Or does it stretch on, maybe up to the point where we reach that second major deadline, the debt limit reached on October 17th?
Far more serious, does this back-and-forth make it more likely that we'll avoid a confrontation over a deadline?
KARL: Well, there are two schools of thought on this. One is that this works out so poorly for the Republicans that they realize they can't go to the brink again over the debt ceiling.
On the other side of this, George, positions have gotten so hardened here and there's such division that it's hard to imagine a compromise on the debt ceiling. Either that said, I should tell you that aides to the Speaker of the House tell me that they are confident that the debt ceiling will be dealt with and there will not be a default.
I just can't see exactly how we get there by October 17th.
STEPHANOPOULOS: Thanks, Jon and we'll have more on that with the round table coming up. But now today's other top story, what could be an historic (inaudible) with Iran.
The man in charge of negotiating with nuclear deal, Foreign minister Dr. Javad Zarif is here live for an exclusive interview.
First, let's go to ABC's chief foreign correspondent Terry Moran for more on a dynamic week of diplomacy.
TERRY MORAN, ABC NEWS CHIEF FOREIGN CORRESPONDENT: Absolutely, George, what we have seen this week represents the possibility of a development of stunning diplomatic breakthrough. But there is a lot of work to do.
MORAN (voice-over): It was a week of head-spinning history in the making.
OBAMA: Just now, I spoke on the phone with President Rouhani of the Islamic Republic of Iran.
MORAN (voice-over): And so with a 15-minute phone call, 34 years of bitter relations thawed ever so slightly.
1979 was the turning point, the shah of Iran, a key American ally, toppled in a revolution, replaced by the fiercely anti-American Ayatollah Ruhollah Khomeini. And a few months later, the storming of the U.S. embassy in Tehran, enemies ever since.
But the election of 64-year-old Hassan Rouhani in June has sparked hope. Rouhani has leashed a charm offensive toward the West, in speeches, on Twitter and in interviews, including with Christiane Amanpour on CNN.
HASSAN ROUHANI, IRANIAN PRESIDENT: I bring peace and friendship.
MORAN (voice-over): So when he arrived in New York this week for a meeting at the U.N., anticipation was running high and Secretary of State Kerry met with his Iranian counterpart Javad Zarif.
But this new chapter is fraught with risk for both sides. After years of deceiving international agencies about its nuclear program, can Iran be trusted? President Obama seems skeptical.
OBAMA: So the test will be meaningful, transparent and verifiable actions.
MORAN (voice-over): Another problem, Rouhani is not the ultimate power in Iran.
Supreme Leader Ayatollah Khomeini is, as Rouhani made clear in his CNN interview.
ROUHANI (through translator): The Supreme Leader has, I can tell you, has given the permission for my government to freely negotiate on these issues.