WASHINGTON – The United States has spent billions of dollars to prevent terrorists from obtaining a weapon of mass destruction even as this week’s bombings in Boston further show that a nuclear weapon or lethal bioagent is not necessary for causing significant harm.
Organized group plots against the U.S. homeland since Sept. 11, 2001 have all involved conventional means of attack. Beyond that have been a handful of instances in which individuals used the postal system to deliver disease materials -- notably this week’s ricin letters to President Obama and at least one senator and the 2001 anthrax mailings.
Terrorism experts offer a range of reasons for why al-Qaida or other violent militants have never met their goal of carrying out a biological, chemical, nuclear or radiological attack on the United States or another nation. These include:
-- substantive efforts by the United States and partner nations to secure the most lethal WMD materials;
-- improved border security and visa checks that deny entry to possible foreign-born terrorists;
-- a lack of imagination and drive on the part of would-be terrorists to pursue the kind of novel but technically difficult attacks that could lead to widespread dispersal of unconventional materials;
-- a general haplessness on the part of the native-born U.S. extremists who have pursued WMD attacks, specifically involving weaponized pathogens;
-- elimination of most of al-Qaida’s original leadership, notably those members with the most experience orchestrating large-scale attacks abroad; and
-- the Arab Spring uprisings have likely drawn down the pool of terrorists with the proper training and focus to organize WMD attacks abroad as they have opted instead to join movements to overthrow governments in places such as Syria and Yemen.
“We killed a lot of people. That was one thing,” said Randall Larsen, founding director of the Bipartisan WMD Terrorism Research Center, referring to the deaths in recent years of al-Qaida chief Osama bin Laden and any number of his direct or philosophical adherents.
Bin Laden is known to have exhorted his followers to seek weapons of mass destruction for use in attacks against the West. Leading al-Qaida propagandist Anwar al-Awlaki of the group’s Yemen affiliate, who was killed in a 2011 U.S. drone strike, used his Inspire magazine to encourage sympathizers to develop and carry out their own chemical and biological attacks.
In the last decade, the technological means to carry out new kinds of improvised WMD attacks such as those involving laboratory-engineered pathogens has become much more available. However, it can take some time for bad actors to recognize how these new technologies can open the doorway to heretofore unseen massively disruptive terrorist attacks, according to Larsen.
Passenger airplanes were flying across the United States for decades before any terrorists realized that they would make a highly destructive improvised weapon when flown at high speeds into skyscrapers filled with thousands of people, Larsen noted.
A 2012 analysis by terrorism experts at the New America Foundation detailed a number of disrupted unconventional weapon plots against the country that counterintuitively were much more likely to involve home-grown antigovernment groups and lone-wolf actors than Muslim extremists. "In the past decade, there is no evidence that jihadist extremists in the United States have acquired or attempted to acquire material to construct CBRN weapons," according to authors Peter Bergen and Jennifer Rowland.
They documented a number of failed domestic plots, often involving cyanide or ricin. Only former Army microbiologist Bruce Ivins was successful in actually carrying out such an effort, killing five people with anthrax spores in 2001.
“Right-wing and left-wing extremist groups and individuals have been far more likely to acquire toxins and to assemble the makings of radiological weapons than al-Qaida sympathizers,” they said.