Despite the optimism, signs of trouble have emerged since the previous round of talks concluded, having missed the declared framework deadline by two days. Key points of the agreement seem to be disputed by the US and Iran, including the question of when and by what mechanism economic sanctions related to Iran’s nuclear program will be removed.

The Wall Street Journal indicated on Wednesday that Iranian President Hassan Rouhani has continued to make remarks emphasizing the need for the complete removal of sanctions immediately after the conclusion of any final agreement. In this, he has essentially parroted one of several red-line declarations by Supreme Leader Ayatollah Ali Khamenei, who has ultimate authority over virtually all Iranian affairs.

This apparent intransigence is sure to amplify concerns about the deal among members of the US Congress who support a more aggressive stance on issues related to the Islamic Republic than does the Obama administration. This opposition to his the administration’s diplomatic agenda is naturally stronger among Republicans than Democrats, but pending legislation to guarantee a congressional role in approving or rejecting any nuclear deal enjoys strong bipartisan support.

This is evidenced both by bill’s unanimous passage through the Senate Foreign Relations Committee on Tuesday and by the decision of President Obama to retract his promise to veto the legislation. This has been presented by the administration as a reaction to recent changes to the bill. But as the Associated Press pointed out on Wednesday, not much has changed. The new version of the bill shortens the mandatory congressional review period from 60 days to 30 days and removes the requirement that Iran demonstrate divestment from former support for global terrorist organizations.

More likely, the cause of the president’s newfound willingness to sign the Iran Nuclear Agreement Review Act (INARA) into law has to do with a political calculation based on the present likelihood that Congress would be able to override a presidential veto. In fact, the Associated Press reports that Secretary of State Kerry was campaigning against the act until just hours before it came up for vote in committee. Subsequently, administration figures have clearly signaled that the president is not happy with the latest developments but is willing to adapt his efforts to the new circumstances.

But it remains to be seen whether the negotiations as a whole will be able to develop to accommodate pressures from both sides without making a final agreement unworkable. The Wall Street Journal indicates that Rouhani has spoken out against the US Congress seeking a role in the negotiations, declaring that Iran is negotiating with diplomats from the P5+1 and not with the American legislature.

But of course Rouhani’s chastisement does not affect the constraints that the INARA will place on his American counterpart. What’s more, Rouhani himself may be further constrained by the Iranian parliament’s reaction to the prospective passage of the INARA. Of course, there is no indication that Rouhani is prepared to accept anything less than full removal of sanctions immediately after the conclusion of the deal, but the parliament has signaled that if Congress pushes ahead with its demand for oversight, Iran will legally bar the acceptance of any agreement that does not meet that current demand.

No such agreement could be expected to pass congressional review, especially given that many political figures, including leading Republicans and contenders for the 2016 presidential nomination, are already decidedly opposed to the deal in its current form. Case in point, Townhall reports that New Jersey Governor Chris Christie spoke about the Iran nuclear issue in a meeting with supporters in New Hampshire and told them that he believes President Obama should back away from the deal currently taking shape.

A similar sentiment was expressed in an editorial published in Investor’s Business Daily on Wednesday comparing the emerging nuclear deal to the ineffective deal struck with North Korea in the 90s when that rogue state was still working toward the nuclear weapon that it has since developed.

The article points out that at the time, Ashton Carter, who is now the defense secretary under Obama, was pushing for a more hardline approach than what was being pursued by the Clinton administration. The article questions why Carter and his colleagues are not now maintaining the same view on Iran and why Carter is not pushing for the same “coercive dimension” to the deal that he advocated for with North Korea, “so economic strangulation and use of military force must be credibly on the table.”

Christie arguably spoke to just such a credible threat on Wednesday when expressed support for the often-worrying prospect of American military forces on the ground in the Middle East. After intimating that Iran should not be utilized as an asset in the conflict against the Islamic State in Iraq and the Levant, Christie said, “We have to be willing as Americans to say, if need be, we’ll also put soldiers into the fight.” Thus far the US has been contributing only air support to the crisis in Iraq, arguably helping to strengthen Iran-backed Shiite militias there.

“They have no basis to have earned our trust,” Christie said of the Iranian regime, adding that its expanding influence and prospective attainment of a nuclear weapon is poised to set off a nuclear arms race across the Middle East.

Yet other informed sources still believe that the nuclear deal, with its present framework, may still be capable of preventing such an outcome and preventing Iran’s further progress toward a nuclear weapon. An article in the National Interest makes the argument that Western intelligence regarding Iran’s nuclear program has been much stronger than some have given it credit for, and that given expanded access to nuclear sites under the emerging deal, it will be entirely possible for international inspectors to remain up-to-date about any efforts by Iran to break out to nuclear weapons capability.

However, this will largely rely on Iran actually conceding to and abiding by an expanded inspections regime. And given the wide range of unresolved issues that will be brought back to the negotiating table when talks resume next week, it remains very much an open question whether the final form of the agreement will still give Western intelligence agencies a leg up on data collection related to Iran’s nuclear program, or whether supporters of such a deal will be able to convince a skeptical Congress that this is the case.