Mark Dubowitz, a sanctions specialist who has advised Congress and the Obama administration, told Congress last week he worries that Iran's supreme leader Ayatollah Ali Khamenei will play for time "by dangling some incremental nuclear concessions before the negotiators, such as the cessation of 20 percent uranium enrichment."
"This concession will be portrayed as an important confidence-building measure, putting pressure on the administration and its partners for a similar gesture in return," Dubowitz said in testimony before the House Foreign Affairs Committee.
During the May 17 hearing, Dubowitz urged lawmakers who have supported tighter sanctions to pressure the administration not to offer "too much relief for too few concessions."
At the same hearing, Mark Wallace, president of United Against Nuclear Iran, a New York-based advocacy group, said Congress should send a strong message to the administration by passing stronger sanctions on Iranian banking, insurance, disclosure and shipping.
Wallace urged lawmakers to make sanctions more "airtight" and said the administration can be more aggressive about enforcing an economic blockade on Iran and pressing EU allies "to not walk back those very important steps that they've taken."
Dubowitz, executive director of the Washington-based Foundation for Defense of Democracies, warned that U.S. and EU negotiators may be tempted to offer "sanctions relief in the shadows." In an interview, Dubowitz said that might take the form of turning a blind eye to discounted Iranian oil exports for struggling EU nations, such as Greece, or setting a lower standard for compliance with some U.S. sanctions.
Obama administration officials and Western diplomats said they have no plans to ease oil sanctions unless Iran dismantles illicit aspects of its nuclear program.
Iran would have to demonstrate significant verifiable concessions before the U.S. and European Union would consider easing penalties that have crippled Iran's ability to export oil, the officials said. Iran earned about $100 billion from oil exports last year, according to International Monetary Fund.