Opponents of the agreement may say that the United States caved and gave up too much. Yet, these same critics have failed to produce a better or realistic option.

Although many issues stand out as most important at this moment in time, as Sen. Jon Tester, D-Mont., recently wrote, the Iran nuclear agreement "will forever shape the future of our state, our nation and our world." As Montana legislators, we join state legislators across this nation to support the Iran agreement. Economic sanctions have not been enough. This agreement provides for aggressive inspections and monitoring. It is our best strategy for preventing Iran from building a nuclear weapon.

The United States originally imposed sanctions on Iran because of the 1979 Iranian Revolution. In 1995 we expanded sanctions by restricting investments in oil, gas and petrochemicals, exports of refined petroleum products, banking and financial services including dealings with the Central Bank of Iran, shipping, web-hosting for commercial purposes, and domain name registration.

In 2006, Iran refused to suspend their uranium enrichment program causing the UN Security Council to join in imposing sanctions. International sanctions have taken a serious toll on Iran's economy and people, but their nuclear weapons development has not stopped.

April 2, 2015, the United States, the United Kingdom, France, China, Russia, Germany, the European Union and Iran completed two years of meetings. The resulting agreement is the best vehicle to prevent Iran from acquiring a nuclear weapon. Inspections and monitoring will be aggressive. Sanctions will be lifted only after Iran meets its end of the deal.

Why not just continue sanctions?

Iran currently has a uranium stockpile large enough to create eight to ten nuclear bombs. This agreement requires Iran to reduce its stockpile of uranium by 98 percent and keep its level of uranium enrichment for power production only, a level significantly below the enrichment level needed to create a bomb.

Right now, Iran has nearly 20,000 centrifuges, enough to create highly enriched uranium for a bomb. Under this deal, Iran will be required to give up most of their centrifuges. They will be allowed to keep only their oldest and least efficient.

Within months, Iran could build a nuclear weapon from the weapons-grade plutonium at their one heavy-water nuclear reactor. Under this deal, this reactor will be redesigned so it cannot produce any weapons-grade plutonium. All Iranian spent fuel rods (which could be source material for weapons-grade plutonium) must be sent out of the country as long as this reactor exists. Iran will not be able to build even one heavy-water reactor for at least 15 years. Because of this deal, Iran will no longer have a source for weapons-grade plutonium

Opponents of the agreement may say that the United States caved and gave up too much. Yet, these same critics have failed to produce a better or realistic option. More sanctions now will not get Iran to capitulate; rather they will likely walk away.

Perhaps the most legitimate concern is that Iran will use sanctions relief to support terrorist activities in the region. Yet, nothing in the agreement constrains the United States and our allies from being able to continue to counter these activities. And while Iran will be getting revenue that has been frozen, many analysts predict the current Iranian administration will use the money to fulfill its electoral mandate: improving the lives of ordinary Iranians.

With all of the misinformation about the deal floating around, and pressure from the opposition, Tester showed great courage in supporting the agreement. We applaud his strong stance and we hope that the U.S. Congress will ultimately be united in support for this good diplomatic agreement that prevents an Iranian nuclear weapon while also preventing war.

State Sen. Sue Malek, D-Missoula, received support for this guest opinion from 21 other Montana Democratic lawmakers, including Sen. Mike Phillips of Bozeman, Sens. Robyn Driscoll and Mary McNally of Billings, Reps Margie MacDonald, Virginia Court and Kathy Kelker of Billings, and Rep. Bridget Smith of Wolf Point.

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