The Knoxville News Sentinel reported that Corker questioned the seriousness of the Obama administration with respect to carrying out aggressive verification of Iran’s commitments. He noted that the deal as it stands fails to impose clear requirements on Tehran to come clean about the past military dimensions of its nuclear program, and that it may leave open too many possibilities for Iran to cheat on inspections.

Much debate has recently emerged over the revelation of provisions that allow Iran to take its own soil samples from certain sites suspected of having links to its military nuclear program. The International Atomic Energy Agency claims that such sampling will take place under a situation of close monitoring, but critics remain worried that such an arrangement puts too much trust in the Iranian regime to provide appropriate and unadulterated samples.

In Wednesday’s hearing, Corker also reportedly derided the Obama administration’s characterization of the nuclear issue as a strict choice between the current agreement and war with Iran. Many opponents of the deal believe that a better agreement is possible or that the United States can force greater Iranian concessions through unilateral economic sanctions and diplomatic pressure. But the deal’s defenders have tended to claim that any unilateral action on the part of the US at this point would put it at odds with the world community, which is already taking steps to invest in Iran and possibly expand diplomatic relations.

On Wednesday, the New York Times reported that French Foreign Minister Laurent Fabius had arrived in Iran for a series of meetings aimed at exploring the way forward for the two countries in the wake of the nuclear deal. France maintained especially strict demands for Iran during the course of negotiations, thus angering hardliners, but Fabius has since claimed that this will not negatively affect trade relations. His schedule of meetings included talks on trade and international business, but also more strictly political discussions.

Fabius’ meetings began a day after EU foreign policy chief Federica Mogherini also visited Iran. On Tuesday, Reuters reported that Iranian Foreign Minister Mohammad Javad Zarif said on the occasion of the visit that the deal might have wider effects, such as collaboration on regional issues. But Iranian Supreme Leader Seyyed Ali Khamenei has explicitly rejected this possibility, at least with respect to the United States, saying in a speech following the nuclear agreement that American and Iranian interests are “180 degrees” opposite to each other.

Of course, many critics of the Iranian regime agree with this assessment, believing that any cooperation with the Islamic Republic would be to the detriment of Western interests and the stability of the Middle East. Reuters reported on Wednesday that United Arab Emirates Minister of State for Foreign Affairs Anwar Gargash had chastised Mogherini for calling for regional and worldwide cooperation with Iran. Gargash claimed that the EU official had failed to grasp the seriousness of Iran’s divisive influence on Middle Eastern affairs, as evidenced by such activities as its support for rebels in Yemen and for the regime of Bashar al-Assad in Syria.

Awareness of this sort of Iranian behavior is also a driving force behind much Western opposition to the nuclear deal as it currently exists. The threat that Iran poses to regional allies including Israel has even led some Democrats to question the Obama administration’s strategy on this point. An article in the Daily Caller on Wednesday highlighted the fact that several Democrats including leading members of the House Foreign Affairs Committee has declared that they are undecided about how they will vote in mid-September after the 60-day congressional review of the deal.

The Daily Caller identifies New York Representatives Eliot Engel and Carolyn Maloney, Florida Representative Debbie Wasserman Schultz, and California Representative Brad Sherman as all having made remarks questioning the weaknesses of the deal and saying that they are on the fence about voting to approve or disapprove of it.

The Blaze also notes that in Tuesday’s Foreign Affairs Committee hearings on the deal, Sherman asked Secretary of State Kerry weather or not he was committed to “following the law” by allowing US sanctions to remain in place if Congress rejects the deal and manages to override President Obama’s veto of that rejection.

Kerry declined to answer the question, leading Sherman to press him on the implication that the administration may be willing to violate US law in order to keep the nuclear deal in place. This in turn may raise questions about whether the administration, over congressional objections, is committed to an overall softer line on Iran, in keeping with the push for cooperation and investment that has lately been seen among European nations.

The Times of Israel reported on Wednesday that new Iranian privileges are still being revealed as the nuclear deal is examined. These include Iran’s apparent access to a worldwide “nuclear fuel bank” to which the US had eagerly denied it access in the past. The bank will allow Iran to sell its own low-enriched uranium in order to move it out of the country in keeping with the deal, but also to buy raw uranium to use in four new nuclear reactors that the Atomic Energy Agency of Iran recently announced it is planning to build.

It is unclear whether US sanctions alone would be sufficient to keep Iran from making such purchases or building such reactors. It is also still unclear whether Congress will be able to gather enough Democratic votes against the deal to keep those sanctions in place, or expand them. Further hearings over the coming weeks may yet sway the opinions of some, including leading Democratic Senator Chuck Schumer, whom opponents of the deal believe would be capable of influencing additional Democrats to vote to disapprove of the agreement.