Buried in the energy bill signed by the president earlier this month are three little lines. The amounts are small, but together they do nothing less than put the United States on the road to developing and eventually testing new nuclear weapons for the first time since the end of the Cold War.

Three little lines, but with potentially shattering impact:

• The bill funds research on new, so-called mini-nukes, nuclear warheads with an explosive power a third or less of the atomic bomb dropped on Hiroshima. In November, the administration succeeded in overcoming bipartisan opposition to lifting a decadelong ban on research and development of such weapons.
• The bill also increased spending on “bunker buster” warheads that can burrow deep into the earth, even through rock, and destroy buried bunkers or command centers.
• Finally, the bill provides money to refurbish the Nevada test site. Underground nuclear tests, halted since 1992, could then resume in a year and a half, rather than the two to three years now needed.

The administration portrays this as part of a revamping of our nuclear arsenal to meet new threats, including the spread of weapons of mass destruction to so-called rogue states. But the military has never asked for nuclear weapons to meet that threat.

The administration dodges this issue by saying this is just research and there are no plans to develop and produce weapons, much less test them. But inside our nuclear establishment everyone has gotten the message loud and clear.

“We should not fail to take advantage of this opportunity,” the administration’s top nuclear administrator, Linton Brooks, said in a triumphant memo to the heads of nuclear labs.

“This administration has made it clear that they’ve gone back into the nuclear weapons business, big time,” said Rep. Ellen Tauscher, D-Calif., one of the most knowledgeable members of Congress on this issue (her San Francisco Bay area district includes the Lawrence Livermore National Laboratory, one of the three nuclear weapons labs in the country).

This shift actually began during the Clinton administration when planners began discussing the need for a post-Cold War role for nuclear weapons. The U.S. nuclear arsenal mainly consists of warheads powerful enough to wipe out a city, mounted on missiles and aimed at Russia and China.

Planners felt the United States needed a more flexible arsenal to face new threats from the proliferation of nuclear and other weapons of mass destruction to countries such as North Korea, Iraq and Iran. If North Korea, for example, used chemical weapons against American troops, the United States would be faced with retaliating with a massive nuclear bomb. It would be a more effective deterrent if the United States could strike back with mini-nukes whose effect would be contained to a small area.

The advocates of this shift are now firmly in command of nuclear policy in the Bush administration and are moving rapidly to implement their views. And while there is room to carry out research in these areas, there are great dangers as well.

Such weapons may not work — experts warn that the radioactive fallout of an underground nuclear explosion will not be contained. Moreover, says former Livermore director Michael May, who authored a recent Stanford University study on this problem, biological agents stored in bunkers may not only not be destroyed but also could be released into the air.

Battlefield nuclear weapons blur the line between nuclear and conventional weapons, undermining the firebreak against nuclear use that held since 1945. This is even more troubling given the administration’s declaration that it won’t hesitate to strike first if it believes rogue nations or organizations have weapons of mass destruction. It lends credence to North Korea’s propaganda that it needs its own nuclear weapons to counter this threat.

Finally, most experts believe such new weapons ideas will eventually require testing, and Russia, China and other nuclear powers will quickly follow. In the end, the world could find itself right back where it was a few decades ago — in the midst of a nuclear arms race no one needs or wants.

Daniel Sneider is foreign affairs columnist for the San Jose Mercury News. His e-mail address is dsneider@mercurynews.com.