A sanctions breather

US Secretary of State John Kerry says he needs a break. "We're asking you to give our negotiators and our experts the time and the space to do their jobs," he said to members of US Congress, "and that includes asking you while we negotiate to hold off imposing new sanctions."

In July, the Republican-controlled US House of Representatives voted to intensify sanctions against Tehran. The recent nuclear accord in Geneva did nothing to soften those sanctions. Opposition to the accord is strong, with many members of Congress fearing it's too lenient on Tehran's leadership and unhappy with the lack of concessions made by Iran.

"We cannot substitute wild-eyed hope for clear-eyed pragmatism given Iran's record of deception," wrote Democratic Senator Bob Mendez, who heads the Senate Committee on Foreign Relations, in a guest commentary in the widely-circulated USA Today newspaper. "Tougher sanctions," he continued, "will serve as an incentive for Iran to verifiably dismantle its nuclear weapons program."

Even President Obama has distanced himself from the agreement.

A task of persuasion

When it comes to sanctions, though, it's the banking committee - and not foreign relations - which holds the strings. And its members can be persuaded by Kerry. Democratic Chairman Tim Johnson and his Republican deputy, Michael Crapo, have made clear they won't be increasing sanctions.

"I support strong sanctions," Johnson said. But Kerry's request for a diplomatic pause is reasonable, the senator added. Should Iran depart from the promises made in Geneva, the US Senate will be quick to pass a new round of sanctions.

Cameron Abadi, an editor at New York-based Foreign Affairs magazine, says Kerry will simply be hoping for the sanctions respite to hold. New sanctions, in his view, would be a sign for Iran that its negotiating partner lacked credibility.

"The hardliners in the Iranian government - especially the Revolutionary Guard - would get the upper hand against the more moderate factions in the Iranian government," Abadi told DW. "And the hardliners, who traditionally have an anti-American ideology, would probably begin to challenge Rouhani and speak out against the [Iranian] president and the deal."

Tensions between the two factions, Abadi added, are already high.

Presidential veto?

According to the Geneva agreement, Iran will reduce stores of weapons-grade uranium by 80 percent and lower current enrichment to levels suitable for domestic energy needs only - all in exchange for an easing of US sanctions.

Some of those sanctions are 30 years old. Others were passed without Congressional approval and can be withdrawn by Obama without consulting Congress, Abadi says. Additionally, the US president can even block new sanctions - at least for a while.

"One option for Obama would be to veto any sanctions that are passed by Congress," he said. "But legally, they'd be on the books. And Obama could promise Iran that he won't apply those sanctions, but the question is whether Iran would trust Obama, given that he's only in office for a few more years and there will be a new president who may have a different attitude."

A sanctions veto would prove politically costly, with Democrats already calling on the president to take a tougher stance.

Six-month timetable

If the accord falls through during the transition phase lasting six months which are yet to begin, many experts say, then so too would the chances of a quicker solution to problems in the region. Syria, with its close relations to Tehran, is an example of where the West could leverage better relations with Iran.

Abadi, however, is skeptical that the accord would have a broader impact throughout the region. "Both Iran and the US are focused pretty closely on this nuclear question, and aren't necessarily interested to extending the negotiations beyond that," he said. New sanctions, therefore, wouldn't have dramatic regional effects.

Although the Senate has dropped the issue at least for now, in the same breath, the US has tightened a different screw: It added Iranian companies and private individuals to its black list of sanctions violators. The firms, apparently, have been supporting Iran's nuclear program. As a result of that decision, Iran on Friday (13.12.2013) withdrew its delegates from a four-day meeting in Vienna where the technical details of the November agreement were meant to be addressed.