Governor Romney at the debate.

At the U.S. presidential debate on foreign policy on Monday night, the effectiveness of Iranian sanctions became a central focus for the two candidates, President Barack Obama and Governor Mitt Romney.

Obama said he has enacted strong sanctions on Iran. “Their oil production has plunged to the lowest level since they were fighting a war with Iraq 20 years ago,” he said. “So their economy is in shambles.”

Romney responded that he would “tighten” Iran sanctions beyond the level that Obama has by going after Iranian shipping and indicting Iranian President Mahmoud Ahmadinejad for inciting genocide.

Despite the candidates’ focus on sanctions, serious doubts remain over their ultimate effectiveness.

In an interview with CNBC prior to the debate, the Governor of the Bank of Israel Stanley Fischer expressed doubt over whether Iran sanctions would collapse its economy. Fischer said that while the Iranian economy would “continue to go down,” the regime likely would “find a way to continue to keep economic life going.”

Meanwhile, the non-partisan Congressional Research Service recently released a report that also cast doubt on sanctions.

“There is a consensus that U.S. and U.N. sanctions have not, to date, accomplished their core strategic objective of compelling Iran to verifiably limit its nuclear development to purely peaceful purposes,” the report said.