The 400-to-20 vote to approve the legislation, known as the Nuclear Iran Prevention Act, came four days before the inauguration of Iran’s President-elect Hassan Rouhani, a moderate cleric who won on a tide of dissatisfaction with the conservative hard-liners who have been in power in Iran for the past eight years. Mr. Rouhani, a former nuclear negotiator, has said he will seek to ease tensions with the United States.
“Iran may have a new president, but its march toward a nuclear program continues,” Representative Ed Royce, a California Republican who was a main sponsor of the bipartisan legislation, said after the vote. “The economic and political pressure on Tehran must be ratcheted up.”
There had been little doubt that the bill, which now goes to the Senate for consideration in September after the Congressional summer recess, would be approved, given the widespread antipathy in Washington for Iran’s government since the 1979 Islamic Revolution.
But the timing of the vote had raised alarm among some lawmakers who contended it would be viewed in Iran as a blatantly hostile signal at a delicate time. Experts in Iranian politics said they feared the vote could embolden Iran’s hard-liners and weaken Mr. Rouhani’s ability to ease the estrangement with the United States.
“They have a strong case to make that they can’t trust us,” said Gary G. Sick, an Iran expert who teaches at Columbia and served on the National Security Council under the Ford, Carter and Reagan administrations, which included the break with Iran. “What the Congress is trying to do is confirm that.”
Mr. Royce and other supporters of the bill rejected that view, arguing that Mr. Rouhani will have limited power under Iran’s supreme leader, Ayatollah Ali Khamenei, who deeply mistrusts the United States. “Cngressional efforts to impose new sanctions should not be based on the Iranian political calendar,” Mr. Royce said.
There appeared to be a cold reception to a letter, signed by 16 representatives, that had urged a delay in the vote. “I hope the recent election makes a difference in Iran, but the only way to ensure it doesn’t is to tell the Iranian people, ‘We don’t care what you do,’ ” said Representative Earl Blumenauer, an Oregon Democrat who signed the letter.
The legislation, if enacted and fully enforced, would theoretically devastate what remains of Iran’s ability to export oil, its most important product, by threatening customers with heavy penalties if they do not find other suppliers. It would also eliminate Iran’s already diminished ability to access money in overseas accounts, and would expand the American sanctions blacklist to include Iran’s automotive, mining, construction and engineering industries. Anyone doing business with those industries would be penalized in the American market, effectively ostracizing them internationally.
The National Iranian American Council, a group that has faulted Iran’s government but opposes sanctions as a negotiation strategy, said the House vote risked squandering a major chance to engage with Iran.