Updated

Overall, Americans are more for military action in Libya than against it, though polling shows varying degrees of support for the coalition effort and pollsters offer several explanations about where backing begins to break down.

An Ipsos poll done for Reuters and released last Thursday shows 60 percent of Americans support allied military action in Libya, and 79 percent agree that the U.S. and its Western allies should try to remove Muammar al-Qaddafi.

According to Ipsos, support for the operation begins to decline when the cost factor is thrown in, while opinions are mixed over whether the U.N. should send in peacekeepers or more aerial bombardment if Qaddafi doesn't fall to airstrikes. Another 20 percent would be okay with the U.S. and allies sending in special forces, according to the polls, but a ground war is favored by just 7 percent.

Despite the high numbers from Ipsos, a Rasmussen Reports survey released on the same day shows only 45 percent of likely U.S. voters support President Obama's decision to join in the coalition effort enforcing a no-fly zone, while 34 percent disagreed. Twenty-one percent were undecided. In the same poll, 47 percent said congressional approval should have been secured before ordering military action.

A Gallup poll conducted last Monday and released Tuesday found 47 percent of Americans approve of the action against Libya with support about equal among both Democrats and Republicans. Only 38 percent of independents surveyed supported the action.

Gallup surmised that the comparable consensus among Democrats and Republicans is likely due to Republicans being generally more supportive of military action while Democrats back Obama administration policies.

Gallup noted that the support, while more positive than negative, is lower than other U.S. military campaigns in the past four decades. Americans supported military action against Afghanistan in 2001 with the most zeal, according to Gallup's surveys, while U.S. airstrikes against Iraq in 1993 and the U.S. invasion of Iraq in 2003 also won greater support than current action against Qaddafi.

However, polling shows higher support for the current campaign than for military actions in Kosovo in the 1990s and Grenada in the 1980s.

President Obama is scheduled to speak Monday night in an address to the nation to explain the purpose of military action, the reason for action against Libya versus other countries and the next steps as NATO takes control and command of the operation that so far has relied heavily on the U.S. Navy capabilities.