Dianne Feinstein, a Democrat, represents California in the U.S. Senate.

Last month, it was revealed that a Pentagon advisory committee authored a report calling for the United States to invest in new nuclear weapons and consider resuming nuclear testing. The report even suggested researching less-powerful nuclear weapons that could be deployed without resorting to full-scale nuclear war. This is terrifying and deserves a swift, full-throated rebuke.

The report comes from the Defense Science Board, a committee made up of civilian experts. The board recommended “a more flexible nuclear enterprise that could produce, if needed, a rapid, tailored nuclear option for limited use.”

Let me be crystal clear: There is no such thing as “limited use” nuclear weapons, and for a Pentagon advisory board to promote their development is absolutely unacceptable. This is even more problematic given President Trump’s comments in support of a nuclear arms race.

As Deputy Defense Secretary Robert Work testified in 2015, “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.”

Nuclear weapons present us with a paradox: We spend billions of dollars building and maintaining them in the hope that we never have to use them. The sole purpose of nuclear weapons must be to deter their use by others. Designing new low-yield nuclear weapons for limited strikes dangerously lowers the threshold for their use. Such a recommendation undermines the stability created by deterrence, thereby increasing the likelihood of sparking an unwinnable nuclear war.

Congress has stopped these reckless efforts in the past. During the George W. Bush administration, attempts to build a new nuclear “bunker buster” weapon were halted thanks to the leadership of then-Rep. David Hobson (R-Ohio).

Today, proponents of building new low-yield nuclear weapons claim that our nuclear arsenal is somehow insufficient to meet evolving threats around the globe. That is simply not true.

First, we already have low-yield weapons: One such bomb, the B61 gravity bomb, is currently being modernized at an estimated cost of as much as $10 billion. Second, our existing arsenal of deployed strategic weapons is more than adequate to deter aggression against us and our allies.

Our nuclear arsenal consists of approximately 4,000 stockpiled warheads, enough to destroy the world several times over. That’s roughly the same number of warheads as Russia and almost four times more than all other countries combined.

We currently have two warheads in reserve for every warhead deployed, a “hedge” of 2 to 1. As we modernize our stockpile, we should strive to reduce both hedge and deployed warheads. In fact, a 2013 report by the Defense Department stated that our deployed arsenal could be further reduced by one-third while maintaining deterrence.

The Defense Science Board also suggested we should consider resuming nuclear testing to have confidence in our nuclear deterrent. That is also a wrongheaded position.

The Energy Department has ensured the safety, security and reliability of the nuclear stockpile for decades without conducting nuclear tests. The department’s work has taught us more about our stockpile than we could ever learn from relying primarily on explosive testing. In fact, the National Nuclear Security Administration has reported that the country is in a better position to maintain the nuclear arsenal than it was before the testing ban went into effect more than 20 years ago.

Resuming nuclear testing would only encourage others to follow suit. The world is made far less safe if other nations begin testing and continue to pursue new nuclear weapons and capabilities. Instead of following the panel’s recommendations, the Pentagon should follow its own 2013 guidance and further reduce our nuclear arsenal in concert with other nations.

To start, we can lead the way by working with Russia to develop a global ban on nuclear-tipped cruise missiles. These weapons are particularly dangerous because they can be mistaken for conventional cruise missiles, increasing the likelihood of an accidental nuclear exchange.

When it comes to nuclear weapons, victory is not measured by who has the most warheads, but by how long we last before someone uses one. This latest proposal may lower the threshold for using nuclear weapons, and the secretary of defense would be wise to reject it.