Americans clearly perceive Iran's potential development of nuclear weapons as a major threat to the U.S. President Barack Obama and Secretary of State John Kerry have positioned the proposed nuclear deal reached on Tuesday as the best way to neutralize that threat. This objective fits with American public opinion, although the particulars of the way in which the new deal reaches that objective will most likely continue to generate significant controversy.

Earlier this year, 77% of Americans said that the development of nuclear weapons by Iran is a critical threat to the vital interests of the U.S. in the next 10 years. That ranks just below the Islamic State group, or ISIS, and international terrorism at the top of a list of potential threats.

Some observers have lauded the agreement for potentially being able to "reshape relations between Iran and the West." Americans would no doubt agree with the need to accomplish that goal, given that their concerns about Iran run long and deep, although with some moderation in the last two years. Between 2006 and 2012, Iran topped the list when Gallup asked Americans to name the country's greatest enemy. Last year, Iran tied with North Korea in second place, behind China. This year, Iran's position on the greatest enemy list fell ever further, named as such by 9% of the public, coming in behind Russia, North Korea and China, and virtually tied with Iraq.

Iran remains one of Americans' least liked countries in the world, as it has since the 1979 revolution. Prior to that event, during which Iranian students ultimately held 52 Americans hostage for 444 days, Americans overall were more positive about the country. This year, 11% of Americans gave Iran a favorable rating, which is less positive than any other country except for the 9% favorable rating North Korea received. Eighty-four percent of Americans view Iran unfavorably.

Agreement May Bring Relief to Many Iranians

In exchange for limiting its nuclear activities, the proposed nuclear deal would reportedly give Iran relief from the economic sanctions imposed by the United Nations, the U.S. and the European Union and allow the country to continue its nuclear program for peaceful purposes. The deal would help revive Iran's economy, which reportedly shrank up to 20% under the sanctions and has lost billions in oil revenue. With most Iranians in late 2014 saying these sanctions had hurt their livelihoods and more than half (56%) approving of Iran developing its own nuclear capabilities for non-military use, both of these aspects of the agreement are likely to find favor with the Iranian public.

While Iranian President Hassan Rouhani said Tuesday that the West and Iran could gradually eliminate distrust if the deal is implemented correctly, this is certain to take time. Iranians' concerns about the U.S. also run long and deep. In the past several years, Iranians' approval ratings of U.S. leadership have typically been among the lowest in the world, ranging from 12% to 15% between 2012 and 2014 as the public held the U.S. chiefly to blame for the sanctions against their country. Iranians' low approval ratings were only supplanted in 2014 by Russia and other post-Soviet states after the crisis in Ukraine and Crimea.

Next Steps

Although the deal has been forged, it is far from done. Several steps remain, not the least of which, Obama must submit the agreement to Congress for review, and in Iran, the country's Supreme Leader, Ayatollah Ali Khamenei, must endorse it. As the future of the deal remains in limbo, so does the future of relations between the West and Iran -- and by extension, Americans and Iranians.