According to a new CBO analysis, nuclear spending in the United States will increase by 28% over the next ten years, compared to forecasts made just two years ago. This prompted complaints that modernization is “far more expensive than expected.” Expenses for national defense should be made clear to legislators. And when it comes to calculating the costs of nuclear weapons, precision is crucial. Because, as Defense Secretary Lloyd Austin has stated, nuclear deterrence is the most important national security mission. The cost of neglecting to upgrade nuclear arsenal is unquantifiable.