WASHINGTON  —  The U.S. Congress moved closer here Wednesday to imposing a full trade embargo against Iran and pledged its support to Israel if it felt compelled to attack Tehran’s nuclear program in self-defense.

The Senate voted 99-0 to adopt a resolution that urged President Barack Obama to fully enforce existing economic sanctions against Iran and to “provide diplomatic, military and economic support” to Israel “in its defense of its territory, people and existence”.

Washington, it said, should support Israel “in accordance with United States law and the constitutional responsibility of Congress to authorize the use of military force” if Israel “is compelled to take military action in legitimate self-defense against Iran’s nuclear weapons program.”

The measure also re-affirmed the official policy of the administration of President Barack Obama that it would take whatever action necessary to “prevent” Iran from acquiring a nuclear weapon.

At the same time, the Foreign Affairs Committee of the Republican-led House of Representatives unanimously approved new sanctions legislation that, if passed into law, would blacklist foreign countries or companies that fail to reduce their oil imports from Iran to virtually nil within 180 days.

The same bill would expand the current blacklisting of companies that do business with Iran’s financial sector to include those engaged in the country’s automotive and mining sectors, as well.

In perhaps its most controversial section, the bill also eliminates President Obama’s ability to waive most sanctions for national-interest or national-security reasons.

Such waiver authority, which has been routinely included in existing sanctions legislation, has been used by Obama to ensure that countries that have historically enjoyed important trade and financial relations with Tehran continue cooperating with Western-led international efforts to pressure Iran to curb its nuclear program.

The president’s waiver authority is also considered critical to prospects for a negotiated agreement between Iran and the P5+1 (U.S., Britain, France, China, Russia plus Germany) by which such curbs would be accepted by Tehran in return for easing sanctions.

Both moves come as the Senate Republicans unveiled yet another bill even more far-reaching than that approved by the House Foreign Affairs Committee by blacklisting companies that do any trade with Iran and deprive the president of all waiver authority. Under the draft legislation, which so far lacks any Democratic co-sponsors, sanctions could be eased or lifted only by an act of Congress.

Approval of both the Senate resolution and the House bill were hailed by American Israel Public Affairs Committee (AIPAC), the premier group of the Israel lobby here.

“The passage of this resolution is an extremely significant and timely state of solidarity with Israel and a restatement of America’s determination to thwart Iran’s nuclear quest – which endangers America, Israeli, and international security,” it said about the Senate action.

The House bill, it noted with approval, would impose a de facto commercial embargo against Iran and would “maximize the effectiveness of American economic and diplomatic efforts as Iran nears a nuclear weapons capability.”

But other observers said the latest Congressional moves marked a dangerous escalation in tensions at a critical moment.

“Congress should abstain from any more reckless threats or sanctions that push us closer to the brink of war with Iran,” Jamal Abdi of the National Iranian American Council (NIAC) said of the Senate action.

“Attacking the president’s waiver authority is a cynical attempt to weaken his hand at the negotiating table and sabotage diplomatic efforts,” he added about the House bill. “If the president can’t lift sanctions in exchange for concessions, the Iranians will have little incentive to cooperate.”

The latest Congressional moves came as the International Atomic Energy Agency (IAEA) released its latest quarterly report on Iran’s nuclear program detailing the installation of more advanced centrifuges that are used to enrich uranium, a buildup of stockpiles of 3.5-percent and 20-percent enriched uranium, and advances in the construction of its heavy-water reactor at Arak.

While a number of senators made much of the latest report, suggesting that Tehran was on the verge of building a nuclear weapon, experts here said that the report offered no major surprises and that Iran’s 20-percent enriched stockpile – which could most easily be further enriched to bomb grade – remained substantially below what Prime Minister Benjamin Netanyahu last September defined as Israel’s “red line”.

“The report findings underscore the urgent need to intensify negotiations with Tehran to resolve the political questions surrounding Iran’s nuclear program and to resolve the outstanding questions regarding the potential military dimensions of the program,” according to an analysis by the Arms Control Association (ACA) here.

“But, at the same time, the findings reinforce earlier assessments that Iran remains years away from obtaining a nuclear weapon.”

Iran has repeatedly denied that its nuclear program is designed to develop a weapon, and, since 2007, the U.S. intelligence community has insisted that the country’s leadership has not yet decided to build one. But the progress Iran has made in building and mastering the technology would shorten the time it would need to construct a bomb if such a decision were made, according to nuclear experts.

On the diplomatic front, meanwhile, progress has been more or less frozen since the latest P5+1 meeting with Iran in Almaty, Kazakhstan in early April when Tehran rejected a Western offer to ease sanctions on gold and precious-metal trade and some Iranian exports in exchange for suspending 20-percent enrichment and transferring its existing 20-percent stockpile out of the country.

Most observers believe the new talks are unlikely until after Iran’s elections next month and the inauguration of a new president, despite the fact that decisions on nuclear issues are ultimately made by the country’s Supreme Leader, Ayatollah Ali Khamenei.

Among the favored candidates approved this week by the Guardian Council is Iran’s nuclear negotiator, Saeed Jalili, who is considered by veteran Iran watchers a hard-liner who has often frustrated his P5+1 interlocutors.

Some had hoped that former president Akbar Hashemi Rafsanjani, who entered the race at the last minute and has occasionally urged better relations with the West, would offer a major challenge, but his candidacy was rejected by the Council.

Another approved candidate in the race, Hasan Rowhani, served as former president Mohammed Khatami’s chief nuclear negotiator. In that post, he struck a deal to suspend enrichment with the so-called EU-3 (Britain, France, and Germany). But his lack of prominence makes him an underdog in a race dominated by conservatives closely associated with Khamenei.

Whether the flurry of new threats and sanctions by Congress will affect the election – or the calculations of Khamenei himself – remains to be seen.

Even the strongest supporters of sanctions have conceded that the economic pressure they’ve exerted on the regime to date has not produced the desired result and may even have strengthened regime hardliners who are convinced that Washington’s ultimate aim is “regime change” – a conviction that is likely to be strengthened by a review of Wednesday’s Senate debate.  

— Jim Lobe’s blog on U.S. foreign policy can be read at //www.lobelog.com.  This article was originally published on IPS.