The survey, conducted from October 16 to 19, 2026, found that 54% of Americans believe the military action against Iran was not worth the costs when weighed against its benefits. Only 23% said the operation was worthwhile, while 20% were uncertain.
Opposition to the military campaign was even higher, with 61% of respondents opposing US attacks on Iran, compared with 34% who supported them.
The opposition was particularly strong among Democrats, 88% of whom opposed the attacks. The figure stood at 66% among independents and respondents with other political affiliations. Similarly, 80% of Democrats and 55% of independents said the costs of the military action outweighed its benefits.
The poll also revealed widespread skepticism about the Trump administration's approach to the war. A total of 58% of respondents said the US government does not have a clear strategy for achieving its objectives in the conflict with Iran, while only 16% believed it had one.
Meanwhile, 78% of Americans expected their country's military confrontation with Iran to continue for an extended period, while just 16% anticipated that the war would end within a few weeks, reflecting public concern that Washington could become embroiled in a protracted conflict.
Economic concerns were also prominent in the findings. As many as 83% of respondents considered a further increase in gasoline prices over the coming month likely, while 79% did not expect consumer goods prices to decline.
The survey further showed that 63% of Americans disapproved of President Donald Trump's handling of the Iran issue, compared with only 25% who approved of his performance.
In another finding, 52% of respondents considered Trump's threatening remarks at the United Nations General Assembly about the destruction of the Islamic Republic of Iran inappropriate.
The Reuters/Ipsos survey was conducted among 1,679 American adults and had a margin of error of 2.4 percentage points.
Overall, the findings point to growing public dissatisfaction with Washington's military policy toward Iran, alongside serious concerns about the war's costs, objectives and potential duration.