Despite its significant shortcomings, we have passed a point of no return. Accepting this deal and moving forward with vigilance and continued commitment to keeping Iran from obtaining a nuclear weapon is preferable to a world in which a debilitated sanctions regime and fractured community of nations allows Iran to acquire many of the benefits of this deal without accepting its meaningful constraints.

Over the past several weeks I have studied the Joint Comprehensive Plan Of Action and exhaustively explored the possible ramifications of this agreement and its alternatives. I’ve consulted with an array of experts on both sides of the debate, sat in classified briefings, discussed it with former and current White House leadership, and benefited from the wise insights of both Republican and Democratic colleagues in the Senate. I also studied Iran and its history, its decades-long efforts to illicitly obtain a nuclear weapon and the evil nature and horrific extent of its support and sponsorship of terrorism, its destabilizing involvement in ongoing regional conflicts, and its destructive hatred and determination to destroy the United States and our ally Israel.

I have come to recognize that on both sides of this debate there are people who want peace and share my fervent determination to prevent Iran from obtaining a nuclear weapon. Both those who support this deal and those who oppose it have reasonable arguments as to why their chosen path is the right one or the better option for preventing a nuclear-armed Iran without the necessity for military conflict.

After hours and hours of study, research, deliberation and consultation, I am more convinced than ever that eliminating the threat of a nuclear-armed Iran is among the most important global security challenges of our time. Allowing Iran to obtain a nuclear weapon would pose an unacceptable and grave threat to the safety of our allies, to Middle East stability, and to American security.

We began negotiations with Iran at a time when our sanctions regime was having its most significant impact on the Iranians. We were gaining maximum leverage on Iran through coordinated economic sanctions with our international partners. We joined with our partner nations at the outset of negotiations with the stated intention of preventing Iran from having the capability to get a nuclear weapon.

Unfortunately, it’s clear we didn’t achieve that objective and have only delayed — not blocked — Iran’s potential nuclear breakout.

But, with the JCPOA, we have now passed a point of no return that we should have never reached, leaving our nation to choose between two imperfect, dangerous and uncertain options. Left with these two choices, I nonetheless believe it is better to support a deeply flawed deal, for the alternative is worse. Thus, I will vote in support of the deal. But the United States must recognize that to make this deal work, we must be more vigilant than ever in fighting Iranian aggression.

Make no mistake, this deal, while falling short of permanently eliminating Iran’s pathways to a nuclear weapon, succeeds in either delaying it or giving us the credible ability to detect significant cheating on their part and respond accordingly. It establishes historically unprecedented mechanisms to block Iran’s near-term pathway to a nuclear weapon. This deal will remove 98 percent of Iran’s enriched uranium stockpile — taking the amount of fissile material from 12,000kg — enough to make multiple bombs — to 300kg, which isn’t close to enough material for even one. None of their enrichment will be underground at the Fordow facility. The agreement will remove and fill with concrete the core of Iran’s heavy water reactor at Arak. The deal will establish the most robust monitoring and inspections regime ever negotiated, covering Iran’s entire nuclear supply chain for 15 years. Some of the most intrusive monitoring, including of its uranium mines and mills and centrifuge production facilities, will last well beyond that period. The agreement will also establish strict limits on Iran’s research and development for the next ten years.

These provisions make this deal an effective framework for preventing Iran from obtaining a nuclear weapon in the near-term, provided we are willing to address infractions — however small they are — with meaningful actions immediately when they occur. And we must take other strong steps to combat Iran’s sponsorship of terrorism and other destabilizing activities.

The deal is also beneficial in that it will give the United States and our allies unprecedented access to, and information about, Iran’s nuclear activities and facilities. Consequently, it will give us intelligence advantages that are extremely valuable in the ongoing effort to prevent Iran from obtaining a nuclear weapon as restrictions in this deal weaken over time.

Further, this deal will maintain unified international pressure on Iran to comply with the terms of the deal or face the re-imposition of sanctions — which can be triggered unilaterally by the United States — or coordinated military action by the United States, Israel and other allies.

But this deal has clear flaws and substantial risks even beyond the obvious and disturbing short duration of its term. With this deal, we are legitimizing a vast and expanding nuclear program in Iran. We are in effect rewarding years of their deception, deceit, and wanton disregard for international law by allowing them to potentially have a domestic nuclear enrichment program at levels beyond what is necessary for a peaceful civil nuclear program.

Further, there is great uncertainty in the future. While several key forms of monitoring will continue in perpetuity, Iran’s opportunity for a nuclear breakout can conceivably become shorter than it is now and much harder to detect given the potential future size and breadth of their program. In essence, we run the risk that, after 15 years, we crowd out the opportunity for diplomacy or effective re-imposition of sanctions. If Iran’s breakout period becomes so short that the transition to a bomb is a step that would take a matter of weeks or days, we may be left with a binary choice between accepting Iran as a nuclear state or taking military action.

This deal is also troubling because after Iran meets its obligations to reduce its stockpiles, reduce their operational centrifuges, and overhaul other elements of their current nuclear program, sanctions will be lifted. It is important to note that sanctions would have been lifted with any negotiated deal, even one with the unlikely terms where Iran gave up their nuclear program entirely. With sanctions lifted, Iran will gain access to tens of billions of dollars and the means with which to greatly improve their economy through trade in the world community.

Even under sanctions and with a crippled economy, Iran had the means with which to fund and arm its destabilizing proxies in the region, support terrorism against Israel, and fund the murderous regime of Bashar Al-Assad. Now, with the deal, the Iranian economy stands to grow five percent annually, creating a potentially more reliable and steady pipeline of funding and resources for destabilizing activities and terrorism. Easing sanctions will further put our allies at risk and demand a far greater level of engagement and investment in the security of the region, particularly our critical ally Israel.

Finally, this deal includes the termination of the United Nations embargo on Iran’s conventional arms and ballistic missile technology after five and eight years, respectively. Even with increased vigilance by the United States and our allies, this will bolster Iran’s conventional weapons threats in the region.

For these reasons, rejecting this deal is a legitimate policy choice that should not be condemned or casually dismissed by those of us who support the deal.

The Alternatives

The reality we now face is one in which we are not comparing the prospects of this deal to a status quo we have known — we’re comparing it to a new alternative, and one that is also deeply troubling. We must recognize that regardless of what Congress decides to do now, our sanctions regime will be significantly weakened.

If we approve the deal, sanctions are significantly rolled back while maintaining the international legitimacy we will need to reconstruct them if Iran cheats. This will be harder to do than most supporters of the deal have portrayed, but far easier to do than if we reject the deal.

If we don’t approve the deal, we risk our sanctions being quickly and thoroughly weakened when other nations and companies worldwide stop cooperating. Future prospects of tightening and enforcing sanctions will dim.

Opponents assert that if Congress rejects the deal and our nation walks away, unilateral sanctions by the United States can maintain serious pressure on Iran. Some opponents of the deal believe that on its own, American economic muscle, pressure, and threats can even force the widespread compliance with sanctions by our allies.

After meeting with sanctions experts on both sides of the debate and studying the issue, I simply disagree.

We must recognize that the sanctions that have severely impacted Iran’s economy have not been just the product of an imposition of American will on our partner nations. They came about through diplomacy and negotiation with other members of the P5+1 with the intention of bringing about a specific end. Our partners in the P5+1 believe we have accomplished that end and will not consent to maintaining the sanctions regime this deal modifies. They will also likely quickly increase already strong pressure to lift the arms and ballistic missile embargoes that are scheduled under the deal to lapse in five and eight years, respectively, as they were put in place in cooperation with our partner nations to force Iran into nuclear compliance.

Pushing back from the table at this point and making a run at unilateral sanctions will lead us to economic conflict with other nations, resulting in pressure placed on the United States as pressure is reduced on Iran. It would force us to make a difficult choice: either we sanction our closest partners — risking damage to our own economy and jeopardizing collaboration with other nations on a host of vital issues — or we don’t and the sanctions regime crumbles.

While our brinksmanship might be convincing to some companies and countries, there would most certainly be companies and countries that would ignore our efforts. The overwhelming evidence indicates that unilateral sanctions will offer a fraction of the benefit that international cooperation brings, and at great cost to the American economy and our global influence.

In light of this, I believe rejection of the deal would allow Iran to achieve an aim it has wanted all along: a significant unwinding of sanctions without the constraints on its nuclear program that this deal provides.

Regardless of our path forward, we are faced with an Iran on the verge of breakout to a nuclear bomb at some point in the next 15 years. If we proceed with the deal, that point likely occurs about 15 years from now, albeit with the added serious concern that the international community has legitimized a significant portion of the path Iran would take to a nuclear weapon.

If we don’t proceed with the deal, we could see Iran immediately ramping up their nuclear program with diminished sanctions and a less united world in the wake of global condemnation of the United States for our disruption of a widely-agreed upon peaceful path forward, supported by more than hundred nations.

There have also been calls for revisiting the deal to achieve a better outcome. After conversations with a range of experts, including current and former diplomats and negotiators, I believe that not to be a realistic possibility. With sanctions weakened if the United States pushes back from the table, and our credibility with both our P5+1 partners and Iran damaged, any deal should one be reached would almost certainly be weaker than the one before us today. I do not ascribe to the school of thought that rejecting the deal will necessarily lead to war, but it will lead to Iran unacceptably close to a bomb, with a strengthened economy, and with reduced isolation.

Our choices have clearly changed. Both of them are problematic. This is not about rejecting the deal and quickly returning to the negotiating table, maintaining anything resembling full-strength sanctions, and getting a better deal. The reality is that rejecting the deal leads to a world in which a better deal is highly improbable, sanctions are greatly reduced in strength, the Iranian economy picks up some steam, and few if any of the benefits of the deal are in place. We need to be honest about our choices — they are bad — and pursue the path that is more likely to provide security for the United States and its allies and best prevents Iran from obtaining a nuclear weapon.

Moving Forward

I believe that entering into this agreement is the right thing to do given our options, but my continued support for this agreement will be contingent upon our government and the governments of our allies treating it as what it is: a limited and imperfect framework designed to regulate Iranian nuclear activity.

We must be more aggressive than ever in fighting Iranian terrorism and containing their proxy wars. This means increased support for our allies in the region, increased intelligence and military cooperation in interdiction and counterterrorism efforts, calling on partner nations — particularly in Europe — to be equally vigilant, and being willing to ratchet up non-nuclear sanctions on Iran when their non-nuclear activities call for it. We must not allow the Iranians to grow the shadow of this agreement to cover non-nuclear activities.

Even under the deal, we should expect that Iran will cheat when it can, particularly at the margins; that it will continue or even ramp up its destabilizing activities and sponsorship of terrorism with the additional resources provided by increased sanctions relief; that it will seek to breakout if the opportunity presents itself after 15 years when specialized inspections fade and many limits on its nuclear program are lifted.

That is why, while I will vote for this deal, I believe we must also pursue a more robust regional strategy aimed at patching the deal’s shortcomings. I have had a series of conversations with the President and various members of the Administration, and have made my very significant, specific concerns clear. Should these concerns not be addressed to a satisfactory extent by the Administration, I will aggressively pursue them through Congressional action.

To address the deal’s shortcomings, the United States must pursue a strategy that includes:

Imposing clear consequences for incremental violations: How we respond to incremental violations starting on Day 1 of the deal will set the tone for the next one to two decades of Iranian compliance. There can be no room for interpretation when it comes to holding Iran accountable for even the smallest violations. The U.S. must make consequences for Iranian transgressions clear and measurable in public statements of policy, and pursue those consequences relentlessly when warranted.

Securing strong commitments from our European Allies: I have asked the Administration to secure a comprehensive set of specific commitments from the heads of state of the United Kingdom, France, and Germany demonstrating their commitment to act with a coordinated response to Iranian cheating and engagement in terrorism and other destabilizing activities, and their support for full implementation of the JCPOA through aggressive inspections and sanctions despite likely increasing economic ties to Iran in the future.

Bolstering interdiction of illicit arms to Iran, and directed from Iran to Hezbollah, Hamas and other terrorists and bad actors: I have requested that the Defense Department provide regular reporting to Congress on maritime security cooperation, with specific reporting on interdiction of conventional weapons destined for Iran and its proxies in the region.

Bolstering Israel’s Qualitative Military Edge: The U.S. should provide Israel with access to the Massive Ordnance Penetrator (MOP) to help deter Iranian cheating. The Administration should also fast-track the completion of a new 10-year Memorandum of Understanding with Israel to bolster our strong bilateral security partnership and cooperation with even greater levels of foreign military financing (FMF). The President has indicated to Congress that these talks will continue, but I would like to see a conclusion reached well before the implementation of this deal.

Renewing the Iran Sanctions Act: The Iran Sanctions Act (ISA) will expire at the end of next year. If sanctions are to snapback in the event of an Iranian violation, we cannot wait for Congress to pass new Iran sanctions. The Iran Sanctions Act must be renewed so that sanctions are at the ready in the instance of Iranian cheating.

Entering into a side agreement with our allies: I request that the Departments of State, Energy, Defense, and our Intelligence apparatus engage in deep dialogue with the relevant Israeli and Gulf agencies to carefully plan for an Iranian violation of the agreement. This agreement should clearly spell out a response to scenarios in which Iran seeks to break out to nuclear bomb production before the agreement lapses, and should include strengthening intelligence cooperation and conducting joint military planning in the event of a violation.

In addition to these items, I will continue to evaluate the situation and work to develop legislative solutions if necessary.

This deal can by no means be a final act in our diplomatic dealings with Iran, but must rather be a beginning of an era of increased vigilance, strict accountability, and rigid oversight. I believe that this attention to detail by which stakeholders on all sides of this issue have advocated will ensure that Congress and future Administrations renew a commitment to stability in the region and maintain the availability of all options, including the use of military force.

As we move forward, we must abandon the heated rhetoric and simplicity of argument that has developed around an issue with such complexity and nuance. If only it were so simple. This deal will not bring absolute security, but nor would its alternative. It will be incumbent on our nation — and on all nations that find the Iranian pursuit of a nuclear weapon unacceptable — to act with resolve, courage, and unwavering determination to ensure that the unthinkable never happens. That requires honest and constructive debate.

While this deal has been a remarkable show of international unity at a time when political and economic cleavages have divided many of the P5+1 countries, evaluating this deal has been one of the most difficult challenges I have faced because of the concerns I have outlined. And make no mistake, I have concerns beyond just these.

Some of the most painful, difficult and influential conversations I have had about this deal have been with valued and trusted friends from the Jewish community who have family members who survived or died in the Holocaust. One New Jersey rabbi and respected friend read me a letter from his grandfather written during the Holocaust calling out to the world to help his children amidst the unthinkable horrors. It was an emotional meeting and it brought me back to my first visit as a young 25 year old to Yad Vashem. I’ve traveled the world, visited graves, memorials, and museums, but none has ever affected me like that first visit. And though the museum was full of stories of righteous men and women, Jews and non-Jews, who answered calls for help, fought against evil, and saved lives among the deaths of millions, a clear lesson is that this monumental tragedy was preventable if only more people recognized evil and took action to stop it.

This realization has left an impression on me that has shaped my outlook on the world and my determination to do all I can to prevent a genocide from occurring again. To be clear: when Iranians chant death to America or pledge themselves to the destruction of Israel, I take them at their word. My Jewish friends and others I have talked with are correct: Iran is an existential threat to the State of Israel and to the Jewish people.

While I may differ with many friends on the choice this deal presents us — and I do believe that this deal presents the better path of two options to stop Iran from obtaining a nuclear weapon — we share precisely the same goal. I am united with all who are determined to ensure that we never again see genocide in the world. That means not allowing Iran to ever obtain a nuclear weapon, period, regardless of what it takes.

This deal does not provide a permanent solution and it is clearly no panacea. It will demand America’s continued principled leadership, and with that leadership offers our best opportunity among limited and flawed options to keep Iran from obtaining a nuclear weapon.