Although last month the Obama administration led a misguided effort in the United Nations Security Council to pass a resolution on nuclear weapons testing, it apparently understands the downside of supporting a treaty to ban nuclear weapons.

In an Oct. 14 statement, the Obama administration rejected a U.N. effort to “declare a ban on nuclear weapons.” As it made clear in the statement:

The United States remains as committed as ever to this goal and to making progress on nuclear disarmament. We have made tremendous progress in reducing the number of nuclear weapons over the last 50 years. Though some are dissatisfied with the pace of disarmament, we remain convinced that the pragmatic and consensus-based approach that has successfully brought us to this point remains the right one going forward.

Today, some states believe the time has come to abandon this pragmatic and consensus-based approach and instead pursue a radically different path that would simply declare a ban on nuclear weapons. We must evaluate this new approach using the same criteria that we apply to our current one. Will it improve global security and stability or undermine it? Will it build a coalition for disarmament or fracture the international community? Will it lead to real reductions in nuclear weapons or be a treaty for political, not practical effect? How can such an approach be verified? The United States has carefully applied these questions to the ban treaty concept and it fails to successfully meet the necessary criteria for success on four counts.

The administration recognizes that banning nuclear weapons “would not lead to any further reductions” since it is unlikely that countries possessing nuclear weapons would sign such a treaty.

Frankly, there is too much distrust between nuclear powers such as the U.S. and Russia or India and Pakistan for a ban to be realistic—none could be sure that the other had complied because verification measures are weak and unlikely to improve.

The issue is threefold. First, states would have to agree to allow unprecedented access to sensitive military and scientific facilities. Second, many technologies that directly contribute to a development of nuclear weapons are legitimately used in civilian nuclear programs. This makes it relatively easy to deceive other states, as Iraq, North Korea, and Iran have shown us.

Third, even when malicious activities are detected, states rarely agree on how to punish the violator and dismantle the nuclear program. In the case of Iran, Tehran was rewarded with billions of dollars and access to modern technologies after decades of deception.

Moreover, with unpredictable states like North Korea and Iran possessing or on the brink of possession of nuclear arms, the risk of abandoning a nuclear deterrent is extraordinarily high.

The Obama administration correctly emphasizes that “nuclear weapons continue to play a role in maintaining peace and stability in some parts of the world.” U.S. allies rely on the U.S. nuclear umbrella and guarantees for their own security. They continue to forego developing their own weapons, even as their own security situation worsens.

The most likely result of the U.S. supporting and abiding by a nuclear ban is not a nuclear-free world, but nuclear proliferation. If the U.S. no longer possesses nuclear weapons, the pressure for our allies to develop and deploy their own nuclear weapons will become overwhelming.

While conservatives should be thankful that the Obama administration understands the foolishness of an outright nuclear weapons ban, that does not mean the current status quo is acceptable. The United States must be certain that its nuclear weapon stockpile remains safe, secure, and effective. Such an understanding is critical for deterring our adversaries and assuring our allies.

Computers are unable to fully replicate the reality of a nuclear explosion, properties of aging materials, and changes introduced into weapons due to new materials. The nation must be able to conduct a nuclear test should circumstances require it.

The Senate rejected an effort to ban nuclear weapons tests in the late 1990s for these and other reasons. The security situation has only gotten worse and more unpredictable since. The administration should take the next step and recognize that an option to test the most important weapons in the U.S. arsenal must remain available.