Americans say Iran poses a greater threat to the US than any other country, and a growing number call Teheran a major threat, according to a new Pew Research Center survey. Americans continue to approve of pre-emptive military attacks in some circumstances, with 63 percent telling pollsters that they would support a US use of force if Iran had produced a nuclear weapon, with only 30% opposed. So far, Americans give US President Barack Obama mixed reviews on his Iran policy, with 43% approving and 40% disapproving. Their attitudes on Iran came against a growing isolationist sentiment in America, which has reached a four-decades high. For the first time in that span, a plurality (49%) think the United States should "mind its own business internationally" and let other countries get along the best they can on their own, the Pew poll released Thursday found. Four years ago, 42% agreed that the US should "mind its own business" in international affairs; in December 2002, just 30% agreed with this statement. Additionally, 44% now agree that because the United States "is the most powerful nation in the world, we should go our own way in international matters, not worrying about whether other countries agree with us or not." That percentage is by far the highest since the question was first posed in the 1960s. Still, Americans continue to sympathize more with Israel than the Palestinians, with just over half, or 51%, saying they sympathize more with the Israelis, while just 12% report that they sympathize with the Palestinians more. Pew points out that these results "have changed little in recent years." When it comes to US policy toward this conflict, Pew assessed the public doesn't have a clear impression. About a quarter can't offer an assessment of current or past American policy. Of those who can, 30% think that the US has favored Israel too much, with 15% saying the United States has favored the Palestinians too much and 29% say past policy has struck the right balance. On Obama, the survey found 51% of Americans think he is striking the right balance with 16% saying he favors the Palestinians too much and 7% saying he favors Israel too much. During his presidency, fears of a terror attack have risen. Now 29% of the public consider the ability of terrorists to attack the United States is greater than it was at the time of the 9/11 attacks, a figure that is 12 points higher than in February. Terrorism continues to be the top international concern, with 76% saying Islamic extremist groups like al-Qaida are a major threat. Iran's nuclear program comes in at 72%, a number that has grown steadily from the 60% who called it a major threat in September 2008. And when asked in an open-ended format which country represents the greatest danger to the US, more Americans cite Iran (21%) than any other country. Iraq and Afghanistan garnered 14% each, 11% said China and 10% answered North Korea. Even so, 76% of those polled say the US should "concentrate more on our own national problems and building up our strength and prosperity here at home" rather than think in international terms, close to a 45-year high. The public also continues to stress that it is more important for President Obama to focus on domestic policy than foreign policy in overwhelming numbers: 73% think Obama should focus on domestic policy and only 12% think he should address foreign policy, consistent with when Obama took office in January. "Tough economic times have always led the American public to turn inward rather than look beyond America's shores," assessed James Lindsay and Parke Nicholson of the Council on Foreign Relations, who collaborated on the survey. "These poll results highlight a potential political problem for President Obama." Specifically, they said, "He campaigned on a pledge to use energetic diplomacy to restore American global leadership. So far, though, his multilateral efforts have come up short. Iran and North Korea refuse to halt their nuclear programs. The Israeli-Palestinian peace process remains frozen." In that context, they continued, "he could face greater political resistance, from both ends of the political spectrum, to his activist foreign policy and multilateralism." The survey of 2,000 members of the general public was conducted via telephone from October 28 to November 8. Interviews were conducted in English and Spanish with a margin of error of three percentage points.