According to a 2013 BBC World Service poll, 5% of Americans view Iranian influence positively, with 87% expressing a negative view, the most unfavorable perception of Iran in the world. On the other hand, research has shown that most Iranians hold a positive attitude about the American people, though not the US government. According to a 2019 survey by IranPoll, 13% of Iranians have a favorable view of the United States, with 86% expressing an unfavorable view, the most unfavorable perception of the United States in the world. According to a 2018 Pew poll, 39% of Americans say that limiting the power and influence of Iran should be a top foreign policy priority. Relations tend to improve when the two countries have overlapping goals, such as repelling Sunni militants during the Iraq War and the intervention against ISIS.