Al Qaeda's ability to conduct terrorist operations against the United States has diminished in the last year, but U.S. intelligence agencies said Tuesday that they now believe Iranian leaders are willing to launch attacks against American targets.
The top U.S. intelligence official, James R. Clapper, told a Senate hearing that a purported Iranian plot to assassinate a Saudi diplomat in Washington in the fall convinced U.S. officials that leaders in Tehran are increasingly likely to support bombings on U.S. soil, especially if they feel that their hold on power is threatened.
"Some Iranian officials, probably including supreme leader Ali Khamenei, have changed their calculus and are now willing to conduct an attack in the United States," said Clapper, director of national intelligence.
Tension with Tehran has risen sharply in recent weeks as the European Union and the Obama administration have imposed punishing economic sanctions in an effort to persuade Iran's leaders to abandon what they suspect is a nuclear weapons program.
Recent reports of bombings in Iran, the crash of a secret CIA surveillance drone there and the assassination of several Iranian nuclear scientists suggest a covert campaign by the West or its proxies is aimed at sabotaging the effort.
America's most senior intelligence officials, including Clapper, CIA Director David H. Petraeus and FBI Director Robert S. Mueller III, testified at the Senate Intelligence Committee hearing on worldwide threats against the United States. Iran was a major topic.
The officials provided no further evidence during the hearing to support their perception of a change in Iranian attitudes.
Iran is "keeping open the option to develop nuclear weapons" and is "technically capable" of producing enough highly enriched uranium to fuel a nuclear weapon, Clapper said.
"We do not know, however, if Iran will eventually decide to build nuclear weapons," he said. Inspectors from the United Nations nuclear watchdog agency are in Iran this week to gather further data on the country's nuclear program. Iran says the effort is aimed at generating electricity, not building weapons.
The CIA believes that Iran is feeling the "increased bite of new sanctions," Petraeus said, referring to the U.S. blacklisting of Iran's central bank. The institution receives revenue for about 70% of the oil sold by the National Iranian Oil Co.
"I think 2012 will be a critical year for convincing or preventing Iran from developing a nuclear weapon," said Sen. Dianne Feinstein (D-Calif.), who chairs the committee. "While the overall terrorist threat may be down, the threat from the proliferation of weapons of mass destruction from Iran and North Korea is growing."
In October, FBI and other federal agents claimed they had disrupted a plot to kill the Saudi Arabian ambassador to the United States by placing a bomb in a Washington restaurant. The alleged plot, which U.S. officials said involved Iran's Revolutionary Guard and a Mexican drug cartel, never moved beyond the planning stages.
Clapper also furnished a 30-page report to the committee on danger spots around the world.
It noted concern about Washington's uneasy partnership with nuclear-armed Pakistan, the rising death toll of drug-related violence in Mexico and Central America, North Korea's push to build nuclear weapons, and the political turmoil in North Africa and the Middle East a year after a series of popular uprisings erupted.
The intelligence officials said that cyber attacks against government agencies and private businesses are growing.
"Down the road, [cyber attacks] will be the No. 1 threat to the country," said Mueller, the FBI director. He said he is working to reorganize the FBI to investigate cyber attacks just as the agency was retooled to respond to terrorist threats over the last decade.
Regarding current threats, Clapper said "lone actors" inspired by terrorist leaders still could conduct limited attacks.
Clapper said U.S. intelligence judged an attack using a dirty bomb, chemical weapons or deadly germs as "unlikely" in the next year.
U.S. airstrikes and drone missile attacks against Al Qaeda in Pakistan and elsewhere have left the organization without central leadership, and a "largely symbolic" role among Islamic extremists, Clapper said.
No charismatic leader has replaced Osama bin Laden, who was killed by Navy SEALs in May, and Clapper said there was a "better than even chance" that the movement will fragment.
Al Qaeda's affiliate in Yemen, known as Al Qaeda in the Arabian Peninsula, remains the most likely group to plan and launch an attack on U.S. soil, Clapper said, but most groups are focused on regional battles.
In Mexico, drug-related killings continue to increase, but the escalating drug violence is not likely to spill across the border, Clapper said.
"The factor that drives most of the bloodshed in Mexico — competition for control of trafficking routes and networks of corrupt officials — is not widely applicable to the small retail drug trafficking activities on the U.S. side of the border," he said.