The executive branch of the US government did not disagree with this assessment, or at least did not do so to a degree that made President Obama willing to veto the bill. But the White House did quickly signal to Iran that it would do everything in its power to limit the extent to which the new rules stymie Iranian business travel. This, naturally, has led to renewed criticisms from Obama’s opponents regarding his supposedly conciliatory approach to dealing with the Islamic Republic.

Newsmax explained in a report on Tuesday that the visa issue had already demonstrated to Congress, and particularly to the Republican Party, that the July 14 Iran nuclear deal between Iran and six world powers had more “strings attached” than some observers had previously reckoned. High-ranking Iranian officials have responded to the American legislation by claiming that restrictions on business travel would negatively affect Iran’s economic prospects and thus violate the spirit of the sanctions relief promised by the nuclear deal.

The Obama administration has tacitly acknowledged this concern. Stephen Mull, who is leading the implementation of the deal on behalf of the State Department, told a Senate Foreign Relations Committee hearing last week that the enforcement of the new visa rules could have negative consequences for the implementation and long-term success of the agreement.

Newsmax points out that by legitimizing the Iranian objections to the visa rules the administration is effectively interpreting “sanctions relief” in perhaps the broadest possible fashion. On this view, it is not enough for Western governments to lift nuclear-related sanctions on the Islamic Republic; they must also facilitate the effectiveness of that relief.

As if to demonstrate the administration’s willingness to do this, Secretary of State John Kerry wrote a letter to Iranian Foreign Minister Javad Zarif on Saturday pointing out that the president has the authority to waive the new requirements. He added that the State Department would be able to expedite the application process for Iranian business travelers and provide them with ten-year, multiple-visit visas.

In another report on Tuesday, Fox News clarified that the  new legislation includes a provision allowing for the Department of Homeland Security to override the requirements if it determines that doing so is in the interest of American national security or the enforcement of international law. It is not yet clear whether the Obama administration will endeavor to apply this provision as a defense against possible threats to nuclear implementation. But the possibility has certainly been introduced to policy circles and to the media.

The national security question highlights the fact that there are fundamental differences between the president and much of Congress regarding the nature of current threats. Last week’s Senate hearing focused much of its attention upon the recent confirmation than a post-nuclear-deal Iranian ballistic missile test violated UN Security Council resolutions. Critics of the Obama administration’s policy are adamant that Tehran be subject to serious consequences for this, and the relative lack of response from the president has justified the notion that his concern is with preserving the nuclear deal even at the expense of extensive concessions to the Islamic Republic.

Omri Ceren of the Israel Project think tank characterized Obama as indicating to the Iranians that “the nuclear deal allows Iran to test ballistic missiles in violation of international law, but does not allow Congress to prevent terrorists from coming into the United States.”

Such criticisms certainly reflect the views of the vast majority of US congressmen, and the Christian Science Monitor claimed on Tuesday that the visa issue has moved that criticism into a new phase. On that issue as on others that have preceded it, Congress is presenting itself as a national security watchdog, pushing back against the Obama administration’s eagerness to defend Iran and speed the nuclear agreement toward full implementation.

Congress has international support from opponents of the Iranian regime, including domestic and expatriate Iranian dissidents affiliated with the National Council of Resistance of Iran. The Monitor quoted a spokesperson for the group as saying that the Obama administration’s response to the visa waiver legislation suggests that it “will bend over backwards to implement the nuclear deal, when actually this is the time when the US should react stronger and show more firmness towards Iran.”

But at the same time that Congress has international support in its attempt to undermine this strategy, it also faces international opposition from other parties that are highly – and often increasingly – interested in facilitating rapprochement and improved trade relations with the Islamic Republic of Iran.

During nuclear negotiations, the French diplomatic team developed a reputation for taking the hardest line on Iran among the P5+1 group of nations. But after a deal was concluded on July 14, France was among the first to send a delegation to explore new business deals in Tehran. And in the aftermath of November’s terrorist attacks in Paris, the French government has focused more narrowly on the conflict with ISIL, which has possibly led to even more outreach to Iran as a potential partner in the same region.

That shift toward rapprochement arguably reached new levels on Tuesday when the Express Tribune reported that Gerard Larcher, the head of the French Senate had explicitly criticized the US visa waiver legislation during a visit to Iran. In the midst of efforts to strengthen relations between Iran and France, Larcher described the visa rules as a “sign of mistrust,” which “sends the wrong signal,” especially in the wake of the UN’s closure of its file on the past military dimensions of the Iranian nuclear program.

But that closure was also controversial within the US, as the final International Atomic Energy Agency Report certified Iran’s recent compliance but also pointed out that its coordinated work on nuclear weapons technology had gone on longer than previously suspected, and had been concealed by the Iranians even up to the last days of the IAEA probe.