American voters oppose U.S. military involvement in Syria, where the government has killed an estimated 7,500 people as it tries to end a year-long uprising. In addition, a majority thinks there should be a national debate before the U.S. intervenes in hot-spots around the world.

Arizona Sen. John McCain has called for U.S. air strikes to help the anti-government rebels -- something the United States did in Libya. A Fox News poll released Thursday shows that a slim 51 percent majority of voters opposes that action, while 37 percent support it.

Click here for full Fox News poll results.

Larger majorities oppose the U.S. providing weapons to anti-government groups (64 percent) and launching air strikes to try to oust the Syrian government (68 percent). Fully 78 percent of voters oppose U.S. troops on the ground in Syria.

Instead of military action, most voters -- 82 percent -- think the United States should provide humanitarian aid.

Current opinion on U.S. involvement in Syria is in line with sentiment last year on Libya. A 55-percent majority opposed military involvement in Libya, and 64 percent opposed providing funding to Libyan rebels (August 29-31, 2011).

President Obama authorized military intervention in Libya without first consulting Congress.

American voters think it should be the other way around. The poll found 59 percent think there must be a national debate and approval from Congress before the U.S. intervenes overseas. That includes majorities of Republicans (65 percent), independents (60 percent) and Democrats (54 percent).

About a third of voters -- 34 percent -- think the president must be able to decide what actions the U.S. should take on his own.

Many voters think the U.S. will soon face such a decision on Iran. A 56 percent majority thinks force will be required to stop Iran from working on nuclear weapons, while 30 percent think diplomacy and sanctions alone will work.

Just under half of voters (49 percent) support U.S. taking military action against Iran. That’s down from 60 percent support last month (February 6-9, 2012).

“With disturbing news coming daily from Afghanistan and Syria, some American’s appear to be reconsidering whether opening another military front right now is a good idea,” says Democratic pollster Chris Anderson, who conducts the Fox News poll with Republican pollster Daron Shaw.

Still, a 61-percent majority thinks the United States should provide military support if Israel attacks Iran.

Fifty-three percent think Israel should take action to keep Iran from getting nukes, while 33 percent disagree.

The Fox News poll is based on land line and cell phone interviews with 912 randomly-chosen registered voters nationwide and was conducted under the joint direction of Anderson Robbins Research (D) and Shaw & Company Research (R) from March 10 to March 12. For the total sample, it has a margin of sampling error of plus or minus 3 percentage points.