Although uranium enrichment can be used for peaceful purposes, it is too easy to use to use this process to make nuclear weapons fuel. The United States has long considered uranium enrichment so dangerous that it has refused to permit it in agreements to share peaceful nuclear technology with friendly states. A series of UN Security Council resolutions have called on Iran to halt uranium enrichment and the installation of enrichment centrifuges.

We know from an April 2, 2015 State Department fact sheet on the nuclear talks that a final nuclear agreement with Iran will essentially concede to Iran the “right” to enrich uranium and will allow it to continue to enrich with thousands of centrifuges. The agreement also will permit Tehran to continue to develop advanced centrifuges that could be eight times more efficient. We believe, given the significant nuclear proliferation dangers of enrichment and Iran’s long record of cheating on nuclear agreements, that a meaningful nuclear agreement with Iran is impossible which allows Tehran to enrich uranium.

The United States must return to its previous position on this issue which the Obama administration abandoned in 2012: any nuclear agreement with Iran must bar uranium enrichment and require that all uranium centrifuges be disassembled – not just “unplugged” – and removed from enrichment facilities. Iran also must send all its enriched uranium stockpile out of the country.

Heavy-water reactors are a serious proliferation concern because plutonium can be extracted from their spent fuel rods. For this reason, the international community strongly discourages developing nations from using this design. The Obama administration made a dangerous concession to Iran on plutonium production.

Although Iran began work on the Arak heavy-water reactor in secret and UN Security Council resolutions have called for work on this reactor to cease, under the nuclear agreement Iran will be permitted to complete construction of this reactor but will replace its core so that it produces less weapons-grade plutonium. Iran disputes this, however, and has said this reactor will be “modernized.”

Even if the core of the Arak reactor is replaced, this concession poses an unacceptable proliferation risk since Iran will be allowed to operate this reactor, which will increase its expertise in this technology. The United States must return to its previous position that work on this reactor be halted permanently.

Assuming the above requirements could be met, a nuclear agreement with Iran must meet a claim made by President Obama in a April 2, 2015 speech that “Iran has also agreed to the most robust and intrusive inspections and transparency regime ever negotiated for any nuclear program in history.” This means full access to all declared and suspected nuclear sites for IAEA inspectors. The inspectors must also be permitted to make “snap,” any time, any place inspections.

The nuclear agreement with Iran currently being finalized falls far short of these requirements. Supreme Leader Ali Khamenei said on May 20, 2015 that he will not allow inspections of military nuclear facilities or interviews with nuclear scientists. Foreign Minister Mohammad Javad Zarif has said there will not be inspections of military sites – the locations where nuclear weapons work is believed to be taking place — in order to protect Iran’s military and economic secrets.

Iran has also rejected snap inspections and will be allowed to contest allegations of covert nuclear activities in a dispute-resolution process, possibly for months. This will give Tehran time to do what it has done repeatedly in the past: sanitize suspect nuclear sites.

On May 27, 2015 French Foreign Minister Laurent Fabius said France would oppose a nuclear deal with Iran if it did not allow inspections of military sites.

The international community cannot confirm that Iran has halted its pursuit of nuclear weapons unless Tehran comes clean on all past and continuing nuclear weapons-related activities. Iran agreed in November 2013 to resolve with the IAEA a list of possible military-related nuclear activities in 12 areas. As of June 2015, Iran has only resolved questions in one of these areas and has claimed the other areas are based on forgeries and fabrications.

A meaningful nuclear agreement with Iran requires answers to these questions to establish a baseline for verification. The United States should not agree to a nuclear deal with Iran until these questions are answered satisfactorily.

We are very concerned about the significant disagreements that clearly exist between the parties about how and when nuclear-related sanctions on Iran will be lifted. Obama administration officials claim sanctions will be lifted in phases, based on Iranian compliance with a final agreement. They contend that all U.S., EU and UN sanctions will be lifted only after the IAEA certifies Iranian compliance with key elements of a final agreement. Even then, these officials insist that such sanctions will only be suspended, not terminated, and will “snap back” if Iran fails to comply with its obligations under the agreement.

We are especially concerned at recent reports that the Obama administration may give Iran a “signing bonus” of $50 billion in sanctions relief immediately after a final agreement is signed. If true, such a concession appears to violate the Corker-Cardin bill which bars the lifting of sanctions against Iran pending a 30-day congressional review.

Iranian officials dispute the Obama administration’s account of how sanctions will be lifted and have declared that sanctions must be immediately terminated, not suspended, after a final agreement is signed.

Even if Iran accepted the U.S. view on how sanctions will be lifted, we still find the Obama administration’s approach to this issue to be unacceptable. We believe the requirements for lifting sanctions are insufficiently rigorous and, therefore, too easy for Iran to meet. For example, it seems unlikely that Tehran will be required to explain past weapons-related activities in order to achieve sanctions relief.

We have similar concerns about a nuclear deal’s sunset provision and its short duration. Based on press reports and Obama administration statements, a nuclear agreement with Iran may last only 10 to 15 years. After this time, Iran will be treated as a “normal” state entitled to any peaceful nuclear technology. We do not believe such a short duration agreement that would quickly legitimize Iran’s nuclear program is in American or international security interests. We believe some dual-use nuclear technologies such as heavy-water reactors and uranium enrichment should always be off limits for Iran and discouraged by the United States.

A nuclear agreement with Iran must lift sanctions carefully in response to proven compliance by Iran. Sanctions relief steps like a huge signing bonus must be avoided since this will sacrifice leverage over Tehran. Even if Iran fully complies with a nuclear agreement, as long as it remains a revolutionary Islamic regime intent on expanding geo-strategic dominance, jihad, and annihilation of the State of Israel, and sponsoring terrorism, there are certain nuclear technologies that the United States must prevent it from acquiring.

The exclusion of Iran’s growing missile program – which includes space launch vehicles that likely are part of an effort to develop ICBM – is a significant flaw of the nuclear agreement under discussion with Iran. Iran’s missile program is too large and diverse to have any purpose other than carrying nuclear warheads. A meaningful nuclear agreement with Iran must require Tehran to significantly curtail its missile program and become a member in good standing of the Missile Technology Control Regime and the Hague Code of Conduct against Ballistic Missile Proliferation.

Iran’s missile program is an essential part of its nuclear weapons program. There cannot be a meaningful nuclear agreement with Iran that does curtail and limit Iran’s missile program.

The nuclear talks have been completely divorced from Iran’s growing interference in Middle East conflicts and its sponsorship of terror. A nuclear agreement which gives Tehran a windfall of billions of dollars in sanctions relief and the release of frozen funds will likely be used to advance its efforts to destabilize the Middle East and its backing of Hezbollah, Hamas and the Houthi rebels in Yemen.

A meaningful nuclear agreement with Iran must require it to end its meddling in regional conflicts, its sponsorship of terror and its cooperation with al-Qaeda.

Iran remains committed to the destruction of the state of Israel. Last November, Supreme Leader Khamenei called for the annihilation of “this barbaric, wolf-like and infanticidal regime of Israel” and issued a nine step plan on how to accomplish this.

America can’t strike an agreement that will provide billions of dollars in sanctions relief with a state that wants to destroy one if its closest friends. The Iranian government must agree to end this hostility toward Israel – including halting shipments of weapons to Hamas and Hezbollah – as part of any nuclear agreement.

Iran is illegally holding four American citizens prisoner: Washington Post reporter Jason Rezaian; Iranian-American Christian pastor Saeed Abedini; former U.S. Marine Amir Hekmati; and former FBI agent Robert Levinson. Rezaian, Abidini and Hekmati have been charged with espionage. Iran claims Levinson’s whereabouts are unknown.

This is not the first time Iran has unlawfully incarcerated American citizens. Such arrests and detentions are intended to humiliate the United States. America cannot strike any agreement with the mullahs of Iran as long as they hold innocent Americans prisoner.