A Reuters video report released on Thursday said only that a conclusion to the talks “appears close,” but little context was given as to what this conclusion was based on. Indeed, reports variously described the end of the process as appearing close in the days prior to the June 30 deadline, and then again in the days prior to the July 7 extension.

Last weekend, US Secretary of State John Kerry admitted that the negotiations could go either way. His remarks to reporters in Vienna referred to Iranian “intransigence,” urged Iranian negotiators to make tough decisions in the days to come, and suggested that the Americans were prepared to walk away from the deal if they did not do so.

But many critics of the Obama administration are skeptical about its actual willingness to leave a deal behind, and to consequently abandon what many believe to be a closely-held legacy goal for the US president. Thus the conservative news site Breitbart speculates that a deal is likely by Friday, and that it will be reached via the Obama administration’s offer of still more concessions to Tehran.

In a webcast panel discussion hosted by the National Council of Resistance of Iran on Wednesday, former White House special envoy on nuclear nonproliferation Robert Joseph declared that the Iranian negotiating party has managed to “squeeze out concession after concession” by manipulating the self-imposed deadlines, raising demands at the last moment, and pushing for extensions.

The White House and some Western negotiators seem to have recently acknowledged that escalating demands and brinksmanship are key aspects of Iranian negotiating strategy. In so doing, however, these same officials suggest that that strategy is testing the limits of American patience. CNN quoted an Obama administration official as saying, “We are seeing pretty standard Iranian tactics that we were ready for.”

Meanwhile, one Western diplomat said, “There will come a point when we are not making progress and then it will be time to come home.”

But if that time comes, it may come after Friday, as CNN contradicts both Reuters and Breitbart by saying that the talks are likely to proceed past that tentative deadline. Breitbart cited an unnamed source at the Vienna negotiations for its claim that a deal is likely. But CNN quoted a close ally of President Obama’s, Illinois Senator Dick Durbin, as saying that the president himself does not view the deal as being as close as some others claim.

In fact, Obama reportedly said that the chances of concluding the deal at all are now “less than 50-50.” This growing pessimism is largely attributable to last minute changes in Iran’s negotiating positions, including its refusal to reveal past military dimensions of its nuclear program and its demand for a lifting of embargos on ballistic missile and conventional weapons shipments to Iran.

On Wednesday, the Christian Science Monitor credited disagreements over the ballistic missile issue with raising tempers in the negotiations, reflecting the severity of Iranian demands and the depth of American resistance to them. Bloomberg reported that Kerry and Iranian Foreign Minister Mohammad Javad Zarif were heard shouting at each other in a closed-door meeting.

That one incident may be indicative of broader tensions, and Bloomberg adds that Zarif has also snapped back at suggestions that Western powers might end the negotiations over Iranian intransigence. “Never threaten the Iranians,” he reportedly said to EU foreign policy chief Federica Mogherini.

In addition to highlighting the conflicts between opposing sides, this incident may also indicate that Iran is as averse to ending the negotiations without an agreement as the Americans are. Foreign policy analyst Michael Ledeen said this week that Iranian Supreme Leader Ali Khamenei may be pushing to avoid a return to the status quo by indefinitely extending the interim agreement that was concluded in November 2013.

According to a reported published Wednesday by the Wall Street Journal, this is a viable outcome and may actually be endorsed and enacted by the Obama administration, as an alternative to walking away from the deal. This possibility also came up in Wednesday’s NCRI panel discussion, with nonproliferation expert Professor Raymond Tanter claiming that that is the most likely outcome.

Ambassador Joseph disagreed, however, and concluded that the Iranians will eventually “take yes for an answer” in the face of a stream of American concessions. But other reports indicate that there may still be some resistance to the full suite of concessions that Tehran hopes to achieve before it will cease delaying and accept a deal.

The Latin American Herald Tribune reported on Wednesday that lead Iranian negotiator Abbas Araqchi claimed an agreement had been reached on all sides with respect to the terms of Iranian sanctions relief. Araqchi insisted that all sanctions would end on day one of any agreement, but many international media reports have pointed out that this is not only at odds with the majority of Western demands, but is also logistically untenable, as many sanctions will require approval from the US Congress or from the UN Security Council before they can be permanently removed.

It is likely, therefore, that Araqchi’s claims overstate the situation and reflect contrasting understandings of what has been agreed. This sort of contrast was on display following the April 2 framework agreement, the English-language provisions of which were disputed by Iran.

Araqchi’s claims regarding sanctions relief are not the only Iranian talking points whose credibility has been called into question. The Jerusalem Post reported on Wednesday that Iran claimed to have put forth a new proposal that it considered a potential final resolution. But Western negotiators responded by saying that they had seen no new proposals, implying that either Iran had lied to the press or had simple re-submitted its prior demands under the guise of a new proposal.

In either case, the Iranian officials’ further comments made clear that they still refuse to concede any of their red lines, such as denial of international inspectors’ access to military sites or nuclear scientists. For the time being, at least, Western negotiators still appear to be resisting concessions on these points. But it remains to be seen whether, and how, these points will be resolved by the current deadline or in the days immediately following it.