Despite warnings that the first-step nuclear deal with Iran is a “historic mistake,” it is safe to say that the sky is not falling. In fact, at the halfway mark of the implementation of the Joint Plan of Action, it is clear that Iran is upholding its commitments — and is actually ahead of schedule in eliminating its stockpile of 20 percent enriched uranium.

Progress toward a final deal also continues. On May 13 in Vienna, political directors from Iran and the members of the United Nations Security Council will meet for a possible seven- to 10-day marathon session where they will begin drafting the text of a final agreement. And despite the relative quiet surrounding the talks, it appears that the sides are finding common ground on some of the most difficult issues.

For example, recent reports indicate that Iran has proposed altering the design of the Arak heavy water reactor to greatly reduce its potential plutonium output, a major potential concession. Former Gen. David Petraeus now even puts the odds of striking a deal above 50 percent, potentially within three months from now.

With all of this positive momentum toward a final deal, the skeptics’ continued warnings and calls for ever-increasing pressure look increasingly out of place. As a result, it is worth reevaluating the cynicism surrounding the negotiations and putting forward new conclusions based upon the diplomatic track record.

Iran Responds to Flexibility, Not Pressure

The threat of increasing sanctions, backed by a threat of military action, has been a constant over the past decade. Therefore, assuming that Iran finally gave in to the pressure is a somewhat dubious assertion. However, the diplomatic equation has changed recently in several significant ways, including a political opening in Iran following the election of President Hassan Rouhani, a pause on new unilateral U.S. sanctions that provided space for negotiations and newfound negotiating flexibility from the Obama administration.

This latter point deserves additional consideration. The Obama administration made two key concessions in the JPOA that were far more significant than the limited, reversible and largely symbolic sanctions relief that has been provided.

First, the Obama administration abandoned the unrealistic and unattainable “zero enrichment” demand by agreeing that Iran would be able to maintain a “mutually defined enrichment program,” upon the conclusion of the diplomatic process.

Second, it agreed that a final nuclear deal would result in the lifting of all UN, multilateral and national “nuclear-related sanctions.” With a concrete view of an acceptable end game, Iran was able to agree to significant concessions in the JPOA — such as eliminating its 20 percent enrichment. This newfound flexibility was likely far more responsible for diplomatic progress than finding the appropriate level of economic punishment. As a result, calls for additional pressure should be ignored.

The U.S. Could Be Less Likely to Uphold a Final Deal Than Iran

The International Atomic Energy Agency has confirmed in monthly reports and recent statements that Iran is implementing the terms it agreed upon in the JPOA — all despite the failure of Iran hawks to pass new sanctions.

This has left opponents of diplomacy grasping for straws. A rumored oil-for-goods deal between Russia and Iran would not be an Iranian violation of the nuclear deal, as some have claimed, because Iran is under no obligation to self-enforce unilateral U.S. sanctions.

While complications could still arise in implementation, there are strong consequences if Iran violates the agreement: The potential failure of diplomacy, the likelihood of increasing economic pressure and renewed consideration of military action.

Further, recent complications in ensuring that Iran receives unfrozen oil revenues under the JPOA foreshadows the much more difficult challenge of lifting sanctions in a final agreement. While the president maintains limited waiver authorities, he does not have the power to lift sanctions unilaterally. That authority rests with Congress, which to date has been more interested in piling on sanctions than removing them. As the JPOA indicates that all nuclear-related sanctions will be lifted in a final deal, there are serious questions as to whether Congress and the administration can work in concert to uphold America’s end of the bargain.

Nuclear Talks Aren’t About Trust, But Verification

Ignore all of the complaints about how we can’t trust Iran. With limitations to Iran’s nuclear capabilities and intrusive inspections, we can verify that Iran’s nuclear program is for peaceful purposes — or detect any Iranian move to break out with sufficient time to respond. If you distrust Iran, you should be for the stringent inspections provided under the JPOA and the expansion of authorities for international inspectors in any final deal. After all, no Nuclear Non-Proliferation Treaty state under this level of IAEA inspection has ever clandestinely broken out and obtained a nuclear weapon.

Further, Iran’s recent diplomacy reflects the polar opposite of a state pursuing nuclear weapons. By inviting inspectors in and agreeing to limitations on its nuclear program, Iran is drastically reducing the chances of a successful breakout. A comprehensive deal would only diminish those chances further.

A Final Nuclear Deal Can Be Struck Within Six Months

There have been numerous distractions over the past three months, including Iran nominating a UN ambassador that served as a translator during the Iran hostage crisis — a formative event for many Americans’ negative perceptions of Iran — and the United States then rejecting that nomination in an apparent violation of international law.

However, these distractions have not yet derailed the negotiating process or diverted the parties from their main goal of striking a nuclear deal. This is likely because all parties know that they have never been this close to reaching agreement. If each side stays on track, there is every reason to believe that an agreeable solution can be struck before the July 20 deadline of the JPOA.

There is, of course, a possibility that the JPOA will need to be extended in three months. While the national security benefits of doing so are clear, an extension would open up an opportunity for opponents on each side to attack the deal and push forward poison pills — such as new U.S. sanctions or restrictions on sanctions relief. Rather than exert additional political capital on fighting domestic opponents yet again, the United States and Iran would be wise to preserve that capital for upholding a deal by reaching agreement by July 20, if possible.

Ryan Costello is a policy fellow with the National Iranian American Council.