JUDY WOODRUFF: The tensions between Saudi Arabia and Iran continued to echo throughout the Persian Gulf today, as Kuwait became the latest Sunni nation to pull its ambassador from Tehran, though it didn't fully cut off diplomatic ties.

But how is this crisis seen from Iran?

We go to William Brangham for that.

WILLIAM BRANGHAM: For more on the story, I'm now joined on the phone by Thomas Erdbrink, who is the New York Times bureau chief in Tehran.

So, Thomas, Saudi Arabia executes this Shiite cleric, Nimr al-Nimr. Protests in Iran against the Saudis get out of hand, and the Saudi Embassy in Iran is destroyed. You reported this morning that the government likely instigated those initial protests, but did they want it to get as far out of hand as it did?

THOMAS ERDBRINK, The New York Times: Just today, one of the heads of the Iranian Revolutionary Guard Corps told to the Fars News Agency that what happened at the embassy was completely unjustifiable, it should have never have happened, and he was sure that his troops were not involved.

And we have been hearing similar comments from other people in the Iranian establishment, which is clearly a sign that either they feel the protests have gone too far or, of course, they have been shocked by the level of blowback from Saudi Arabia, and are now trying to do some damage control.

The focus completely shifted toward them because of their own actions. And this is what actually the Iranian officials are telling me off the record: Look, we don't like to admit it, but we shoved ourselves to the front by doing this.

WILLIAM BRANGHAM: You report that this crisis comes at a time when Iran was really hoping to emerge as a growing power in the Middle East. They just signed a nuclear deal. Sanctions were soon to be eased. President Rouhani was hoping to be celebrating, not be dealing with this.

So, what does this mean for him and for other reformers in Iran?

THOMAS ERDBRINK: Well, of course, Mr. Rouhani came to power with the promise of mending relations with other countries.

The historic nuclear deal was a clear example of his administration going out, negotiating for two — for two full years, and then getting Iran a deal that its supreme leader, Ayatollah Khamenei, could sign off on. So, that, by itself, was a major boost for President Rouhani.

But, of course, now, in a time that he was hoping to see the result of those negotiations, and sanctions are about to be lifted in the coming days or weeks, he is faced with the remains of the Saudi Arabian Embassy.

And several countries, Bahrain, the United Arab Emirates and two other nations have either completely disconnected their diplomatic relations with Iran or have at least seriously downgraded them.

So, for President Rouhani, this is a setback. At the same time, he is trying literally to come out with a more positive spin on this. He's been condemning, like many other officials, what happened at the embassy. And, of course, the Iranians are hoping that, in the long run, it will be, in the end, Saudi Arabia that will come out as the bad guy, if you will, out of this.

WILLIAM BRANGHAM: Let's look a little bit more broadly in the region. Does this jeopardize the larger diplomatic initiatives that Iran was involved in, the talks about ending the Syrian civil war and the fighting in Yemen? What does this crisis do to those efforts?

THOMAS ERDBRINK: Well, it's absolutely a major obstacle.

And let's face it. Iran is a player in those two theaters that you mentioned. It allegedly supports the Houthi rebels in Yemen. And, of course, it supports President Bashar al-Assad in Syria.

Iran has just, through negotiations, gotten so far that it was invited in these major talks that we're seeing every couple months on Saudi Arabia. The next one is about the take place on January 25. But now the whole debate has shifted towards the relationship between Iran and Saudi Arabia, instead of solving the crisis inside Syria.

So, if that meeting will still happen on the 25th, will the — will Saudi Arabia allow it? Will Iran go along as it is now? Because we don't know how this will spin out of control. So all and all, this is a major obstacle to peace in Syria and Yemen.

WILLIAM BRANGHAM: Again, does this indicate that the Saudis intentionally killed Nimr now to incite this very reaction and set back the talks because they didn't like the way they were heading?

THOMAS ERDBRINK: Well, absolutely.

That's what the Iranians will also tell you. They feel as if a trap was laid out for them, and they sort of stepped in it with their eyes closed.

The view of the Iranians is that Saudi Arabia has always been their regional competitor. So, whenever there is a conflict involving a Shia minority, or, for instance, the execution of this Shia ayatollah in Saudi Arabia, the Iranians feel as if the Saudis are actually trying to hurt them.

WILLIAM BRANGHAM: Thomas Erdbrink of The New York Times, thank you very much.

THOMAS ERDBRINK: Thank you.