Broad legislation allowing for sanctions against Iran swept through the Senate Banking Committee and House Foreign Affairs Committee last week with overwhelming support.

The sanctions' committee passages represent Congress' toughening stance toward Iran, even as the Obama administration works to give diplomacy a chance.

"We must send a clear signal to Iran's leaders that, if they continue to defy the will of the international community, our nation is prepared to confront them on that," said Banking Committee Chairman Sen. Chris Dodd.

The Senate bill authorizes a ban on direct imports from Iran to the US and exports from the US to Iran, for all products except food and medicine. The House bill would also expand sanctions on Iran substantially, pressuring global energy companies to divest from the country, blocking its refined petroleum imports, urging the president to sever investments in the central bank of Iran and authorizing sanctions on US businesses with ties to Iranian petroleum.

A mandate that Iran cease all uranium enrichment before sanctions are lifted was added to the House version of the bill prior to committee passage.

"The world, and I mean both our allies and others, needs to know that the US Congress is dead serious about sanctions should diplomacy fail to resolve the real concerns about Iran's nuclear program," said Rep. Gary Ackerman (D-New York), chairman of the House Foreign Affairs Subcommittee on the Middle East and South Asia, at last week's hearing.

Pressuring Obama on Iran?

The Obama administration, however, isn't quite ready to determine whether diplomacy has "failed," and the president is conspicuously reserving judgment when it comes to the sanctions legislation.

In fact, "the State Department actually did not want to see this happen," according to Sen. Bob Corker (R-Tennessee), the sanctions bill's one Banking Committee skeptic, who nevertheless voted for the legislation.

When senators requested the administration's position on the sanctions bill, Deputy Secretary of State James Steinberg openly refused to comment, ruffling the feathers of panelists - including many of the committee's Democrats, who are urging the president to adopt a harder line on Iran.

"I find it troubling that the administration is not looking to support the toughest sanctions possible," Sen. Charles Schumer (D-New York) told The Hill last Tuesday.

Currently, the US and Iran, along with other key powers, are negotiating a means to deal with Iran's supply of enriched uranium. Iranian officials have rejected a plan to ship much of Iran's uranium to Russia to be converted into fuel rods for civilian use, according to the latest reports.

Taking steps toward sanctions is a hasty move in this critical time for diplomacy, according to Kingston Reif, the deputy director of nuclear nonproliferation at the Center for Arms Control and Non-Proliferation.

"The sanctions legislation can only hurt US diplomatic efforts," Reif said. "The Obama administration has not asked for and has not reached a judgment on whether they would be helpful. Congressional supporters of sanctions say that they do not mean to preempt or undermine the President's ongoing diplomatic efforts. Yet as Corker put it, unilateral sanctions are 'a tacit vote of no confidence' in the negotiations. They send the signal that we have no interest in letting the talks run their course."

The Senate version of the sanctions bill would forbid the president from lifting the embargo on Iran without an O.K. from Congress.

Enabling Ahmadinejad, Hurting Iranians?

Opponents of the sanctions bills say they'll have little impact on Iran's government. According to Reif, US sanctions may actually act as a scapegoat, enabling the Ahmadinejad administration to enact widely unpopular domestic policy changes, such as slashing the amount of gas that Iranians can buy at subsidized prices.

"The government of Iran spends 10 to 20 percent of Iran's GDP subsidizing imported gasoline," Reif said. "The regime wants to put an end to these subsidies but has not done so due to fears of a public backlash. Sanctions could give Ahmadinejad and his ilk the perfect excuse to end the subsidies, which would enrich the regime at the expense of the Iranian people."

Critics of the Foreign Affairs Committee legislation say it will allow Iran's government to foment nationalist sentiments while eschewing the democratic fervor that emerged during the summer's post-election protests. An op-ed by Rep. Keith Ellison, published in The Hill a week before the Committee vote, argues that sanctions will only unite the Iranian government and people against the United States.

"Increasing sanctions enables the Iranian president the opportunity to change the subject - from his failed policies to the nationalistic pride symbolized by nuclear energy," Ellison writes.

Opposition to the sanctions is already mounting on all sides within Iran. Iranian Nobel Peace Prize winner Shirin Ebadi has noted that sanctions would persecute Iran's poor and encourage solidarity with the government.

Though US Congress members have cited the turmoil following Iran's election as a rationale for sanctions, many human rights activists - and former presidential candidate Mir Hossein Mousavi himself - say an embargo would worsen the Iranian people's predicament.

"Sanctions would not actually act against the government - rather, they would only inflict grave distress against a people who have experienced enough disaster in their own melancholic statesmen," Mousavi said. "We are opposed to any types of sanctions against our nation."

Farrah Hassen, a fellow at the Institute for Policy Studies, notes that, historically, sanctions have a dismal success rate. In both Iraq and Cuba, they failed to alter the behavior of the targeted governments, but hit the general population hard, making it difficult for civilians to obtain basic supplies and precipitating a humanitarian crisis.

Sanctions reliably amplify the voices of anti-American leaders, and could subvert the goals of Iran's "green revolution," according to Hassen.

"If anything, [sanctions] could strengthen Iran's hardliners, confirm their suspicions that the US under President Obama is not serious about relations based on 'mutual interest' and 'mutual respect,' allowing officials the excuse to justify economic woes, mismanagement and other internal challenges on the sanctions - dealing further blows to reformists and activists still recovering from the wounds of the disputed June 12 election," Hassen said.

Instead of imposing sanctions, Hassen suggests that Washington work toward an "acceptable compromise," conceding that Iran need not completely dismantle its nuclear program, but should open its doors to ongoing international nuclear inspections.

Leaving the Military Option Open

Throughout the House and Senate committee hearings floated inklings of what might lie beyond the sharpening sanctions: Some Congress members - including a solid contingent of Democrats - are contemplating military intervention in Iran.

"Even as we proceed - as we must - on enhancing our capacity for unilateral sanctions, and even as we continue - as we must - on developing crippling multilateral sanctions that can be applied if diplomacy proves ineffectual, we should bear in mind that there may not be any level of sanctions sufficient to compel a change in Iran's nuclear program," Rep. Ackerman stated prior to Wednesday's hearing.

Ackerman argued for a "comprehensive" Iran policy that "enhances political and military coordination in the Persian Gulf."

Rep. Ileana Ros-Lehtinen, ranking Republican member of the House Foreign Affairs Committee, has had similarly menacing words when it comes to future US-Iran engagement.

"Iran poses an even greater threat to Israel + 2 US security interests," Ros-Lehtinen posted to her Twitter page prior to the sanctions vote. In the past, she has stated that if Israel should choose to take military action against Iran, "I believe the U.S. will stand shoulder to shoulder with Israel."

According to Reif, the sanctions legislation enjoys widespread support and is likely to pass both the House and the Senate when it reaches the floor.

However, as long as the Obama administration stays mum on its position, advocates of diplomacy can hold out hope that the president will oppose the imposition of "crippling sanctions" and avoid the specter of a humanitarian crisis - not to mention skyrocketing anti-Americanism - in Iran.