Press Releases

Washington—Senator Dianne Feinstein (D-Calif.) joined with 12 Senate colleagues demanding the Defense and Energy departments reject a recent Pentagon report that called for new “limited-use” nuclear weapons and suggested ending the nuclear testing ban.

“There is no such thing as a limited nuclear war, and the United States should be seeking to raise the threshold for nuclear use, not blur that threshold by building additional so-called low-yield weapons,” wrote the senators.

Full text of the letter is available below.

March 14, 2017

The Honorable James Mattis
Secretary of Defense
U.S. Department of Defense
1400 Defense Pentagon
Washington, DC 20301

The Honorable Rick Perry
Secretary of Energy
U.S. Department of Energy
1000 Independence Ave. SW
Washington, DC 20585

Dear Secretary Mattis and Secretary Perry:

We write today in opposition to two nuclear weapons-related recommendations outlined in the Defense Science Board's most recent report, “Seven Defense Priorities for the New Administration.” The report encourages the Departments of Defense and Energy to build new nuclear weapons and questioned their ability to maintain our nuclear warheads in the absence of testing, which we wholly reject.

Specifically, the Defense Science Board recommends “a more flexible nuclear enterprise that could produce, if needed, a rapid, tailored nuclear option for limited use.” We strongly believe that there is no such thing as the limited use of nuclear weapons or limited nuclear war. In fact, the Board's recommendation reminds us of an effort by the Bush Administration to build a new nuclear weapon specifically designed to destroy deeply buried enemy targets. That program, named the Robust Nuclear Earth Penetrator, or a nuclear “bunker buster,” was halted by the leadership of former Republican Congressman David Hobson in 2005.

The only role of nuclear weapons is to deter their use by others and we are aware of no evidence demonstrating that new nuclear weapons are needed to preserve or enhance deterrence. Our nation's security is better protected by investments in advanced conventional weapons, not new nuclear weapons.

We also fundamentally disagree with the Board's belief in the utility of limited nuclear use. There is no such thing as a limited nuclear war, and the United States should be seeking to raise the threshold for nuclear use, not blur that threshold by building additional so-called low-yield weapons. We strongly agree with Deputy Secretary Work's testimony last year when he stated: “anyone who thinks they can control escalation through the use of nuclear weapons is literally playing with fire. Escalation is escalation, and nuclear use would be the ultimate escalation.”

Additionally, as you know, U.S. nuclear capabilities are already highly credible, flexible, and lethal. The arsenal includes lower-yield weapons that can produce more “limited” effects, including the B61 gravity bomb, which is being modernized at an estimated cost of as much as $10 billion.

Finally, we do not believe it is an “open question,” as the board claims, whether the science-based Stockpile Stewardship Program and associated nuclear warhead life extension programs can maintain our confidence in the long-term reliability of our nuclear deterrent. The Department of Energy has for decades supported the capacity of the scientists and supercomputers at the National Laboratories to ensure the safety, security, and reliability of the nuclear stockpile without conducting nuclear tests. This program of subcritical experimentation has worked, and has taught us more about our stockpile than explosive testing would have.

Additionally, in 2015, the three nuclear weapons lab directors reported that the country was in a better position to maintain the nuclear arsenal than it was during the era of test explosions, which ended more than 20 years ago. We strongly believe that the United States does not need to resume nuclear testing, which will only encourage others to do the same. Instead, we should seek to reinforce the global norm against nuclear weapons testing.

As you know, the United States is already planning to undertake a trillion-dollar nuclear sustainment and recapitalization program that includes investments in refurbished nuclear weapons and their associated delivery systems and supporting infrastructure. Successfully executing this program while simultaneously modernizing our conventional forces presents an enormous challenge.

While we appreciate the work of the Defense Science Board, we strongly disagree with the wisdom or need to develop new nuclear weapons or resume nuclear testing. For 71 years the United States has led the world in opposition to the use of nuclear weapons, leadership that would be called into question should the United States develop new, so-called low-yield nuclear weapons. As you prepare to lead the Trump administration’s review of U.S. nuclear policy and posture, we urge you not to act on the Board's recommendations.


Dianne Feinstein
United States Senator

Edward J. Markey
United States Senator

Richard J. Durbin
United States Senator

Patrick Leahy
United States Senator

Ron Wyden
United States Senator

Sherrod Brown
United States Senator

Al Franken
United States Senator

Tammy Baldwin
United States Senator

Jeffrey Merkley
United States Senator

Bernard Sanders
United States Senator

Brian Schatz
United States Senator

Chris Van Hollen
United States Senator

Kamala D. Harris
United States Senator