CNN: Americans skeptical Iran will stick to nuclear deal

(CNN)President Barack Obama's big policy win this week -- preventing Congress from blocking the nuclear agreement with Iran -- may do little to improve his sagging approval ratings.

A new CNN/ORC poll finds 59% disapprove of the way Obama is handling the U.S. relationship with Iran, and about half would have preferred Congress reject the deal. Few believe Iran will abide by its terms, and a growing number consider the country a serious threat to the U.S.

Most Americans think Iran will ultimately violate the terms of the agreement, with 37% calling that extremely likely and 23% saying very likely. Just 10% think it's not at all likely that Iran would break the agreement. Republicans (83% likely) and independents (58% likely) are more apt to believe Iran would violate the agreement than are Democrats (44% likely).

If Iran did violate the deal, 64% of all adults say the United States should respond with military action, including majorities across party lines (57% of Democrats, 64% of independents and 72% of Republicans). About a third, 34%, say the United States should not take military action if the deal is broken.

Perceptions of threats from North Korea, Russia and Iran have all grown since April, but the biggest increase lies with Iran.

Nearly half (49%) now say they consider Iran a "very serious" threat to the United States, up 10 points since April. That shift came across party lines with double-digit increases in the percentage viewing Iran as a very serious threat among both Democrats (up 14 points to 43%) and Republicans (up 15 points to 68%). Fewer see North Korea (37%) or Russia (30%) as a very serious threat, but both those figures have increased 5 points since April.

Overall, 52% disapprove of Obama's handling of the presidency, while 45% approve. This marks the second straight poll where a majority disapproves of Obama following a late spring/early summer flip into positive territory.

In the new poll, nearly four in 10 (37%) say they disapprove strongly, while just 20% have a strongly positive view. Majorities disapprove of Obama's handling of the economy (53%) and foreign affairs (55%), and the public is about evenly split on his management of climate change (47% approve while 44% disapprove), the issue at the center of his recent trip to Alaska.

Personally, Obama is slightly better liked than his work, though not by much. The public splits evenly, with 49% having a favorable impression of the president and 49% an unfavorable one.

On the domestic front, impressions of the economy appear to be rebounding from their summer slump, with 48% now describing it as in good shape and 51% saying it's poor. In July, just 41% thought the economy was in good shape.

The 6% who call the economy "very good" in the new poll is the highest share to say so since December 2007. And most say they expect the economy to be in good shape a year from now (54%). Still, the optimism isn't shining as brightly as it did in April, when 60% said they expected a good economy a year from now.

But there is no such optimism on the nuclear agreement with Iran, which only about half wanted to see approved. As the Democratic coalition that prevented congressional Republicans from blocking the agreement grew, so did public support for approving the deal.

Overall, 47% in the poll said Congress should approve the deal, up from 41% saying so in August. The poll was in the field when the number of senators in support of the deal reached 41, enough to prevent the Senate from overriding a presidential veto of any bill rejecting the agreement. Still, 49% said they thought the deal ought to be rejected.

The CNN/ORC poll was conducted by telephone September 4-8 among a random national sample of 1,012 adults. Results for the full sample have a margin of sampling error of plus or minus 3 percentage points.