Poll: Americans' views on foreign policy

CBS News Poll analysis by the CBS News Polling Unit: Sarah Dutton, Jennifer De Pinto, Fred Backus and Anthony Salvanto.

Ahead of the CBS News/National Journal Republican presidential debate on national security and foreign policy taking place on Saturday night in South Carolina, CBS News surveyed Americans to find out their views on Iran, China, Israel, North Korea and other countries; their feelings about whether the Afghanistan and Iraq wars have been worth the cost; and which of the Republican candidates are most ready to serve as commander-in-chief and to handle an international crisis.

Preview: GOP candidates ready for CBS News/National Journal debate

Here are highlights from the poll:

• More than three in four Americans - 77 percent - approve of Mr. Obama's decision to withdraw U.S. troops from Iraq by the end of the year. Two in three say the war was not worth the cost.
• Republican primary voters see Mitt Romney and Newt Gingrich as the presidential candidates most qualified to lead the military and handle a crisis abroad.
• One in two Americans say U.S. should not have gotten involved in Libya; seven in ten oppose U.S. efforts to transform dictatorships into democracies.
• Most Americans believe the threats posted by Iran and North Korea can be contained without military action.
• More than half of Republicans hold an unfavorable view of Islam.

The Candidates:

Asked which GOP presidential candidate is most qualified to be commander-in-chief, Republican primary voters chose Mitt Romney more than any other candidate, at 26 percent. Close behind Romney was Newt Gingrich, who was chosen by 21 percent of respondents.

Gingrich was cited by GOP primary voters as the candidate they most trust to handle an international crisis, with 31 percent naming him; Romney came in at 19 percent. On both questions, none of the other candidates exceeded 11 percent support. (Read more from the poll on views of the candidates.)

Afghanistan and Iraq:

A majority of Americans - 53 percent - say the United States should not be involved in Afghanistan. Only 36 percent say the U.S. is doing the right thing in fighting there. Republicans are more likely than Democrats to support the war, but even among that group, 43 percent say the United States should not be involved.

Still, more Americans say the war is going well - 48 percent - than say it is going badly - 42 percent.

Fifty-eight percent of Americans say troop levels should be decreased in Afghanistan, including 68 percent of Democrats. Twenty-seven percent want troop levels kept where they are, and 8 percent want them increased. President Obama announced in June that the 33,000 so-called "surge" troops he deployed to Afghanistan would be home by September 2012, though that would still leave nearly 70,000 troops in the country.

More than three in four Americans - 77 percent - approve of Mr. Obama's decision to withdraw U.S. troops from Iraq by the end of the year. That includes 63 percent of Republicans. Seventeen percent overall disapprove of the decision.

Two in three Americans, including half of Republicans, say the Iraq war was not worth the loss of life and costs that came with it. Just 24 percent say the war was worth it.

Terrorism and counterterrorism:

Forty-two percent of Americans say the United States and its allies are winning the war against terrorism - the same percentage that says no one is winning that war. Nine percent say the terrorists are winning.

Thirty-six percent of Americans say the Obama administration's policies have made the country safer from terrorism - up from 28 percent last May - while 34 percent say they've had no effect and 19 percent say they've made Americans less safe.

Sixty-five percent say they support U.S. military action in countries like Pakistan and Yemen where terrorists are believed to be hiding, which is often achieved through drone attacks. Twenty-two percent disapprove.

Following the killing of American citizen and terrorist Anwar al-Awlaki in Yemen, 53 percent of Americans say it is acceptable to kill an American citizen abroad if he or she is a known terrorist. Thirty-five percent say it is not acceptable.

Forty-five percent of Americans say waterboarding can be justified, while 40 percent say it is not justified. Republicans (79 percent) are far more likely than Democrats (35 percent) and independents (37 percent) to say waterboarding can be justified.

A slim majority of Americans - 52 percent - want the prison at Guantanamo Bay, Cuba to remain open. One in three want to close the facility, which holds enemy combatants who have been captured in the war against terrorism. Though Mr. Obama has vowed to close the prison, he has yet to do so; only 44 percent of Democrats say they want it closed.

Libya and U.S. intervention abroad:

Despite the removal of Muammar Qaddafi from power without American lives being lose, half of Americans say the United States should not have been a part of the military conflict in Libya. Thirty-seven percent say the United States did the right thing.

Americans are split on the question of whether or not the U.S. should use military force to try to prevent violent attacks against civilians by foreign governments. Thirty-nine percent say it should, and 39 percent say it should not; 14 percent say it depends. Americans are similarly divided whether they are Republican, Democrat or independent.

Seven in ten Americans say the U.S. should not try to change dictatorships into Democracies. Just 15 percent say the U.S. should attempt to do so.

Israel, Palestinians and Islam:

Forty-one percent of Americans call Israel an ally, including 58 percent of Republicans and 29 percent of Democrats. Thirty-four percent describe the nation as friendly but not an ally. Seven percent describe it as unfriendly, and five percent call it an enemy.

While thirty-eight percent say America gives the right amount of support to Israel, nearly one in three says the U.S. supports Israel too much. Seventeen percent - including 26 percent of Republicans - say the U.S. supports Israel too little.

Forty-two percent of Americans support the establishment of a Palestinian state that is recognized by the United Nations, while 34 percent are opposed to it; 22 percent aren't sure.

One in four Americans say they have a favorable view of Islam, but a larger percentage - 32 percent - hold a not favorable view. That includes 52 percent of Republicans.

Asked if Islam encourages more violence than other religions, 36 percent of Americans, including half of Republicans, say yes. Forty-two percent say it encourages the same amount of violence, while 6 percent say it encourages less violence.

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Iran:

A majority of Americans - 55 percent - say the threat posed by Iran, which has been developing a nuclear capability, can be contained by diplomacy. Fifteen percent say the situation requires the United States to take military action now; 17 percent say Iran is not a threat. Republicans are more than twice as likely as Democrats to say Iran is a threat that requires military action.

North Korea:

Responses are similar when it comes to North Korea, which 65 percent of Americans say the threat can be contained. Sixteen percent overall say the threat requires military action now, while 12 percent say the nation is not a threat.

China:

About half of Americans describe China, which holds more U.S. debt than any other country, as friendly but not an ally. Eleven percent says the nation is an ally, while 20 percent describe it as unfriendly and 12 percent call it an enemy.

There are widespread concerns about China's economic expansion and military. Sixty-one percent say the nation's economic expansion has a generally bad effect on the United States, while 67 percent say its military poses a threat to the U.S. - including one in four who describe the threat as major.

Pakistan:

A majority of Americans say Pakistan - the nation where Osama bin Laden was found hiding, and where the U.S. has been sending unmanned drones to attack terrorists - is either unfriendly (39 percent) or an enemy (24 percent). Twenty-one percent say the nation is friendly but not an ally, and two percent call it an ally.

The CBS News/National Journal debate on national security and foreign policy, from Spartanburg, S.C., begins at 8 p.m. ET on Saturday -- watch on the CBS Television Network or here at CBSNews.com.

Read the complete poll (PDF)