Democratic senators are reluctant to press President Obama to take more aggressive action against Iran despite the efforts of some of their colleagues.

As tensions rise in the Middle East and an Israeli military strike seems imminent, Sens. Lindsey Graham (R-S.C.) and Joe Lieberman (I-Conn.) are spearheading a resolution calling on Congress to rule out any foreign policy approach that would accept Iran as a regional power with nuclear strike capability. Sen. John McCain (R-Ariz.) is also involved. 

But their attempts to recruit Democratic lawmakers to their cause is falling short, as Democrats are showing an aversion to interfering with the commander in chief during an election year.

{mosads}This comes despite the sway of the men involved: Graham, Lieberman and McCain are considered some of the top foreign policy experts in the upper chamber and they often travel together on codels, the official trips lawmakers take to foreign countries.

They have had some success: Sen. Bob Casey Jr. (D-Pa.) has signed on, and one source familiar with the legislative strategy said Sen. Richard Blumenthal (D-Conn.) is also on board. 

The measure is expected to be unveiled later this week, and the trio was scrambling to persuade more Democrats to sign on by midweek. 

Democrats worry the resolution would be seen as creeping toward an authorization of military force against Iran, a foreign policy option that is highly unpopular with liberal voters. 

A Senate aide familiar with the resolution said it is not an authorization of military action and leaves the option of further negotiations on the table. 

Graham and Lieberman announced last month they planned to introduce a bipartisan resolution that will “put the Senate on record as ruling out a strategy of containment of a nuclear-armed Iran.” 

They, and others in Congress, worry the administration views Iran’s development of a nuclear weapon as inevitable, and are preparing to employ a variation of the containment policy the United States used against the Soviet Union during the Cold War. 

Spokesmen for the lawmakers declined to discuss negotiations with potential Democratic allies. Spokeswomen for Casey and Blumenthal declined to comment on the resolution.  

This is the latest effort by Congress to push Obama to take a tougher stand against Iran’s scramble for enriched uranium, which threatens to destabilize the region.  

The Senate voted 100-0 in December to require the administration to impose sanctions on Iran’s financial sector. Obama ordered tougher sanctions on Iran’s central bank earlier this month, but critics say the administration went only as far as the new law required. 

Growing aggression between Iran and Israel has fueled new worries on Capitol Hill. 

Iranian President Mahmoud Ahmadinejad said over the weekend that he will soon announce a major nuclear development. 

Israel on Monday accused Iran of masterminding bomb attacks against embassy workers in India and Georgia. The bombings appeared to be retaliation for the assassination of Iranian nuclear scientists by a similar method, attaching a magnetic explosive to a car. 

Earlier this month, Defense Secretary Leon Panetta predicted Israel will launch a military strike against Iran in the next several months to prevent it from building a nuclear warhead. 

Some lawmakers and policy experts believe Obama is prepared to accept a nuclear-armed Iran. 

“Many in Congress suspect correctly that Barack Obama has every intention of tolerating Iran with a nuclear weapon despite his protestations to the contrary,” said Danielle Pletka, vice president of foreign and defense policy at the American Enterprise Institute. “The administration seems more concerned about an Israeli strike on Iran than Iran acquiring a nuclear weapon.”

Graham, Lieberman and McCain are dead set against accepting Iran as a nuclear power, and want the administration and Congress to make an unequivocal statement that the United States will pursue all means to avert that possibility. 

“Iran with a nuclear weapon is great concern and will further destabilize a volatile region. Sen. Graham thinks Iran getting a nuclear weapon is a disaster in the making,” said Graham’s spokesman, Kevin Bishop. 

Alex Vatanka, a scholar at the Middle East Institute, said the resolution is not necessarily a preliminary step to military action against Iran, although some might view it as such. 

“It acts as part of the U.S. pressure on Tehran. Some would argue this is part of the build-up to war with Iran but the step in itself would not fundamentally change the U.S. position,” he said. “President Obama has never ruled out the military option.”

Vatanka, who answered questions by email from Dubai, said Iran’s neighbors fear another U.S. military campaign in the Middle East could have broad consequences.  

“I sense a lot of anxiety about what a U.S. war against Iran would mean to the region,” he said of Iran’s neighbors. “This is despite huge reservations in these states about Iranian behavior and policies.

“The U.S. pro-war argument certainly has many detractors here in the Middle East and that’s why I think to put the military option as the default mechanism to deal with a nuclear-armed Iran is to unduly limit U.S. policy options,” he said.