President Barack Obama has narrowed the range of instances under which the United States would unleash its nuclear arsenal, but the new strategy doesn't abandon "first use" of the ultimate weapon of mass destruction.
Mr. Obama, who next week will host a summit of world leaders intended to make progress toward a nuclear-weapons-free world, unveiled his new strategy Tuesday, saying he wants to "reduce the role of nuclear weapons while preserving our military superiority, deterring aggression and safeguarding the security of the American people."
Under the policy, the U.S. will not launch a nuclear attack against any country that signs the Nuclear Non-Proliferation Treaty and abides by it, a loophole leaving both North Korea and Iran on any potential target list. It also pledges not to use nuclear weapons against non-nuclear countries, officials said, in contrast to previous administrations, which reserved the right to retaliate for a biological or chemical attack by a non-nuclear state. But Mr. Obama included a major caveat: The countries must be in compliance with their non-proliferation obligations under international treaties. That means Iran would remain on the potential target list.
Over all, the policy promised less than many had expected. "It's a very modest document … it's surprisingly status quo," said Hans Kristensen, director of the Nuclear Information Project, at the Federation of American Scientists, the group founded in 1945 by scientists who had worked on the Manhattan Project to develop the nuclear bomb dropped on Hiroshima and Nagasaki.
As expected, the first-strike option was retained as the new promises not to use nuclear weapons against non-nuclear-armed states are hedged.
Mr. Obama, who vowed a year ago to aim for a nuclear-weapons-free world has just completed a new arms-reduction pact with Moscow that will cut weapons by roughly one-third but still leave both the U.S. and Russia with thousands of warheads. Coupled with Tuesday's new strategy, the stage is set for the nuclear summit he will host next week where much emphasis will be on non-proliferation and the dangers of extremists getting even a single nuclear warhead.
In the administration's view, terrorists with a stolen warhead in the back of a truck or a shipping container poses the biggest danger. "The greatest threat to U.S. and global security is no longer a nuclear exchange between nations, but nuclear terrorism by violent extremists and nuclear proliferation to an increasing number of states," Mr. Obama said.
Mr. Kristensen cautioned against placing too much focus on the spectre of a stolen warhead. "It may be that the terrorist threat has become the most likely, but it is still not the greatest threat," he said, referring to the diminished but still terrifying possibility of a massive nuclear weapons exchange.
Mr. Obama's Nuclear Posture Review says the U.S. won't launch a nuclear attack against any country that signs the Non-Proliferation Treaty and abides by it, leaving North Korea and Iran on any potential target list.
"All options are on the table when it comes to countries in that category," Defence Secretary Robert Gates said, referring to Iran and North Korea.
The 74-page review, a Congressionally mandated Defence Department document doesn't bind the president. Rather, it reflects Mr. Obama's new approach to the controversial but vital issue of nuclear weapons and their use.
Micah Zenko, a conflict prevention specialist at the Council on Foreign Relations, said Mr. Obama's efforts to win widespread support for non-proliferation efforts - including securing nuclear materials and building momentum for sanctions against Tehran - will be helped by the pragmatic but clear commitment to reducing the role of nuclear weapons in the United States' own arsenal.
However, even the pledge not to use nuclear weapons against non-nuclear-armed states is hedged.
"Given the catastrophic potential of biological weapons and the rapid pace of bio-technology development, the United States reserves the right to make any adjustment in the assurance that may be warranted by the evolution and proliferation of the biological weapons threat and U.S. capacities to counter that threat," the review says, effectively warning that if a country managed to weaponize anthrax and threatened the United States, the Obama administration might consider a nuclear first strike.
"This does not mean that our willingness to use nuclear weapons against countries not covered by the new assurance has in any way increased. Indeed, the United States wishes to stress that it would only consider the use of nuclear weapons in extreme circumstances to defend the vital interests of the United States or its allies and partners," the review says.
As the first and still only country to use nuclear weapons and as the world's sole remaining superpower, The United States' posture on non-proliferation and nuclear disarmament is often viewed with being designed to retain an overwhelming military advantage over other countries.