Deputy Foreign Minister Abbas Araqchi will head the session from the Iranian side for its first two days, opposite his US counterpart, Wendy Sherman. Their superiors, Iranian Foreign Minister Mohammad Javad Zarif and US Secretary of State John Kerry will join the talks for Saturday and Sunday.

Functioning as a supplement to formal negotiating sessions between Iran and the P5+1 group of nations, these bilateral talks are said to be aimed at narrowing the persistent gaps between the American and Iranian negotiating positions. But progress in this regard has been hard to come by, largely because of the intransigence of Iranian positions, including refusal to diminish the country’s current nuclear enrichment capacity and resistance to an expanded relationship with inspectors from the International Atomic Energy Agency.

In keeping with that latter point, it was widely reported on Thursday that the latest IAEA documents still show Iran to be stonewalling key aspects of the probe into the possible military dimensions of Iran’s nuclear program. That program has been taking place separate from, but alongside the P5+1 negotiations, and its outcome has long been expected to play a role in determining whether Western negotiators would accept a final deal.

The Associated Press reports that Iran continues to respond to IAEA inquiries by simply denying any prior pursuit of nuclear arms, instead of actually taking steps to prove its innocence. The IAEA report indicates that the regime has still not provided adequate explanations for activities that have long been a source of suspicion among nuclear negotiators and Western intelligence agencies. Tehran’s denials contradict the findings of those agencies, but without corroborating evidence.

The IAEA does, however, give Tehran credit for honoring commitments to temporarily restrain its nuclear enrichment program while the probe and the P5+1 negotiations are going on. However, pending legislation in the Iranian parliament promises to immediately resume and expand full-scale enrichment as soon as those negotiations fail and the US re-imposes economic sanctions on the Islamic Republic. Furthermore, Iranian Supreme Leader Ayatollah Ali Khamenei has made clear Iran’s intentions to dramatically expand that enrichment program in coming years even if a deal is concluded with the West.

The likelihood of that deal is presumably diminished by Iran’s obstruction of the IAEA probe. In addition, its lack of transparency raises questions about the international community’s ability to truly verify that Iran is maintaining the limits it claims to have agreed to. Many of the IAEA’s suspicions relate to sites like the Parchin military base, to which Iran has frequently barred inspector access, citing privileges related to its refusal to agree to the Additional Protocol of the Nuclear Non-Proliferation Treaty.

Owing to this obstructionism, one senior diplomat said of the IAEA probe, “with respect to PMD, progress is very slow, if there is any progress at all at this point in time.” For opponents of the current Western approach to negotiations, this is a crucial deficiency, as current US proposals threaten to leave Iran in possession of the vast majority of its present enrichment capability. Experts differ in their assessment of the length of time that it would take Iran to enrich enough uranium for a nuclear weapon given roughly 6,000 operation centrifuges, with some concluding that the “breakout time” would be about six months and others indicating that it may be only several weeks.

In any event the danger of such breakout is much amplified if Iran already has the other essential capabilities to weaponize its uranium stockpile. And as long as the IAEA probe falters, the international community simply does not know what Iran’s relevant capabilities are.

This danger is surely much greater for Iran’s regional rivals, including the state of Israel, which many Iranian officials have sworn to destroy completely. The Israeli government is thus highly critical of US President Barack Obama’s negotiating strategy, which Israeli Prime Minister Benjamin Netanyahu has described as giving away nearly 80 percent of Iran’s demands.

This criticism and the American response has reportedly driving a serious wedge between the usually close allies, and the Global Post on Friday quoted Israeli politics professor Gideon Rahat as saying that relations between the two countries are at the worst they have been in 20 years. Rahat questions why the Netanyahu is pushing the issue to the extent that it is, as by accepting an invitation to speak to a joint session of the US Congress on March 3, over President Obama’s objections.

Rahat implies that Netanyahu’s motives might be political, comprising an effort to exploit a wedge issue in the weeks immediately prior to parliamentary elections in Israel. But it is at least as likely that the Israeli Prime Minister is genuinely concerned about Obama giving away the store to Iran, especially at a time when Iran’s influence in the region is growing even in absence of the additional leverage provided by a nuclear weapon.

Illustrating that point and its relevance to Israel, The Tower reported on Thursday that the Palestinian terrorist group Hamas had announced plans to dispatch military units to Lebanon to fight Israel on that front alongside Hezbollah, the Iran-backed Shiite paramilitary. The move seems to indicate a growing closeness between opponents of the Jewish state – a closeness managed by Iran, which has also begun to entrench its own forces along with Hezbollah fighters in the Syrian portion of the Golan Heights, just over the border from Israel.

Various foreign policy analysts have concluded that Iran’s expansion of regional influence demonstrates a strategy of encircling both Israel and Saudi Arabia, Iran’s traditional Sunni rival. This may go a long way toward explaining the urgency of some opposition to the Obama administration’s dealings with Iran. Some have attempted to reconcile the American and Israeli perspectives on the issue, albeit with limited success.

The Jewish Press reported on Thursday that two former US envoys have proposed verification methods and US-Israeli defense agreements as means of providing Israel with some guarantee that swift action will be taken in the event that Iran rushes for a nuclear weapon or cheats on any nuclear deal that might be signed in June. But the Jewish Press rejects these proposals as being based on the faulty assumption that you can “guarantee the behavior of a rogue Islamic Republic.”

Retired Israeli Brigadier General Yosef Kuperwasser told reporters that Iran simply cannot be trusted to comply with a deal, even in spite of Western efforts at verification and enforcement. He suggested that a conciliatory approach to negotiating with the Islamic Republic has given the impression that the US isn’t serious about constraining Iran, prompting the regime to continue moving forward with its nuclear weapons program, albeit cautiously.