The hands of the so-called "Doomsday Clock" might be moved closer to midnight later this month. The clock is a symbol of the Chicago-based Bulletin of the Atomic Scientists, and signifies how close the publication's editors thinks the world is to nuclear destruction.
The Bulletin created the clock in 1947 and through the years it tracked how dangerous the world had become as a result of the Cold War. It has never been moved as a result of terrorism because until now, Bulletin publisher Stephen Schwartz says terrorism has not altered the global security landscape.
"One of the most important things that we have to consider is that the moral and ethical barriers that have been in place since 1945 against using weapons of mass destruction to kill large numbers of innocent people have fallen now," he said. "It is very clear that al-Qaida, if it had access to nuclear weapons or nuclear weapons materials, would use them."
The clock's hands are now set at nine minutes to midnight, but that could change when the publication's board meets later this month.
Schwartz says he does not think terrorists will build a nuclear weapon anytime soon because of the extensive expertise needed to build one. But he says the myth that terrorists do not kill large numbers of people has been destroyed.
He says as a result, the American people have some tough decisions to make in the future. "Some of the issues of things we might have to reassess: do we really need to maintain a large contingent of troops in Saudi Arabia?" he said. "Is that something that Americans are going to be willing to fight and die for in the future?"
The presence of American troops in Saudi Arabia is among the things al-Qaida terrorist network leader Osama bin Laden has said fuels his hatred of the United States.
The last time the hands of the Doomsday Clock were moved was three years ago, after India and Pakistan tested nuclear weapons.