Homeland Security Secretary Michael Chertoff downplayed the threat of a nuclear terror attack Friday despite recent postings on al-Qaida-affiliated Web sites exhorting militants to pursue weapons of mass destruction for use against the U.S.
Speaking at London's Oxford Union, Chertoff said that while officials acknowledge al-Qaida's interest in developing such capability, the U.S. was more concerned about terrorists' use of conventional arms.
"The short answer is the intent is there. Its probability, particularly in the short term, is lower than conventional weapons," he told the students and journalists in attendance at the famed debating society.
Chertoff's remarks followed a series of anonymous postings on al-Qaida-affliated Web sites, including a 39-minute video, calling on militants to acquire weapons of mass destruction.
The Washington-based SITE Intelligence Group, which monitors militant Web traffic, said the video presents the U.S. as vulnerable and suggests that militants could use such weapons as a deterrent to any nuclear attack against an Islamic country.
Although none of the postings are known to be authentic, taken together they raise questions about whether jihadists have such capabilities and whether they can launch some kind of attack.
But Chertoff downplayed the idea.
"In the immediate or near term, the focus is on conventional weapons, which can still be quite damaging. Something on the scale of 9/11 or the attacks on your transportation system. We have to look at the whole spectrum," he said.
The video is part of a propaganda campaign to frighten the West, SITE director Rita Katz said.
"It's just an indication of the strong desire that jihadists have for the use of such a weapon, but I don't see a reason to worry about a WMD attack in the U.S. based on this chatter," she said.
Ben Venzke, CEO of the IntelCenter intelligence group, said the video is probably not made by al-Qaida but has been put together by someone who sympathizes with their aims.
"They take clips from everywhere — the BBC, old Bin Laden clips and edit them together. The mention of weapons of mass destruction is just wishful thinking," he said.