Iranian stalling tactics, veiled threats from the six powers, an odd PowerPoint presentation about religious rulings by Iranian spiritual leader Ali Khamenei, and nary a word about Israel: That is some of what happened behind closed doors at Moscow's Golden Ring Hotel, where a third round of nuclear talks with Iran took place this week.

The intensive talks held in Moscow on Monday and Tuesday between Iran and the six powers - the United States, Russia, China, Britain, France and Germany - ended in failure. The six powers were unable to bridge their major gaps with Iran.

A Western diplomat who asked to remain anonymous in light of the sensitivity of the talks said that one major obstacle revealed by the Moscow talks relates to the underground facility for uranium enrichment in Fordo, near the city of Qum.

According to the diplomat, the Iranians responded only in a broad, vague fashion to demands that it limit its enrichment of uranium to a level of 20 percent and move such uranium outside the country, and they refused to discuss the Fordo plant at all. The Iranians claimed that Fordo is not a military facility, so it should not be included in the talks.

"We learned that Fordo is a taboo subject for the Iranians, and that it is the flagship of their nuclear project," the diplomat said.

After ending the second round of talks in Baghdad with the feeling that the six powers were desperate to forge an agreement, the Iranian delegates arrived in Moscow feeling confident. But Western diplomats, who realized that expectations had been raised too high in Baghdad, came to Moscow skeptical and cautious. The message they broadcast was that the powers want an agreement, but not at any price.

The Western diplomat said that several times during the Moscow talks, Western representatives conveyed veiled threats and warnings to the Iranian delegation. The message was that "we are not under pressure, and we prefer no deal to a bad deal."

Western delegates, he added, told the Iranians that "packing our bags and going home won't be a problem. That won't cause anything bad to happen to us. But if you are the ones to pack your bags and leave, you'll have a lot to lose."

The six powers presented tough terms to the Iranians, and they rejected Iran's request to conduct a fourth round of talks with higher-level representatives. "Another round of talks like this one will not lead to results, so we told the Iranians that there's no point in holding them," the Western diplomat said.

They did agree to arrange a meeting of jurists and nuclear experts to conduct a detailed review of the positions presented by both sides during the Moscow discussions. But the powers made it clear to the Iranians that they "want concrete actions, not just talks."

The Iranians were surprised that delegates from the six powers managed to maintain a united front throughout the discussions. The Iranians had hoped to bring the Chinese and Russian delegates into their corner. But during separate meetings with the Russian and Chinese diplomats, the Iranians heard the same message that was relayed consistently in the meetings with representatives from all six countries.

Throughout the Moscow negotiations, Saeed Jalili, head of the Iranian delegation, tried to carry out delaying tactics and evasive maneuvers. One odd moment occurred on the second day of the discussions, when the Iranians announced that they were willing to discuss an initiative broached by Russia's President Vladimir Putin regarding the nuclear dispute.

Delegates from the six powers began passing notes among themselves in an effort to ascertain what Putin's initiative actually said. Some of the diplomats in the conference room sent text messages to colleagues outside, asking that they conduct Google searches to see whether Putin had sponsored an initiative they didn't know about.

After a few minutes of searches, it became clear that the initiative in question was actually an article published by Putin four months ago, during his presidential campaign. Putin stated in the article that Iran should be allowed to enrich uranium under certain restrictions, to be monitored and enforced by the International Atomic Energy Agency. The agitated Russian delegation hastily explained that this article was not a formal diplomatic initiative and bore no relevance to the diplomatic negotiations then underway.