When Defense Secretary Chuck Hagel entered the Obama administration, he was a proponent of U.S. unilateral nuclear weapons reductions. He believed that nuclear weapons are irrelevant and that the U.S. would be better off getting rid of them.

Now, he’s resigned—and his change of opinion on nuclear weapons might surprise you.

Hagel leaves after having proposed to spend an additional $1.5 billion a year on nuclear forces to mitigate issues identified in this month’s Independent Review of the Department of Defense Nuclear Enterprise (the Independent Review) and the Pentagon’s own review. The increase in investment is overdue and must be maintained by the next secretary of defense. Indeed, the problem the next secretary will face is President Obama’s commitment to reducing the U.S. nuclear deterrent.

In 2009, President Obama declared his desire for a world without nuclear weapons. Although he promised to maintain the U.S. nuclear deterrent, he negotiated the New Strategic Arms Reduction Treaty with Russia and then retreated on his nuclear modernization promises when the first opportunity presented itself. New START failed, and Russia today deploys more nuclear warheads than the United States. The president promised to speed up the Chemical Metallurgy Research Replacement Facility at Los Alamos, but the administration cancelled the plan a year after New START entered into force. The president promised to deploy all four phases of the European Phased Adaptive Approach, a missile defense plan for the protection of the United States and the European allies, but the administration canceled the last phase of the EPAA last year.

In Berlin in 2013, Obama declared his desire to further reduce the U.S. nuclear arsenal by a third. Reality interfered yet again when it became clear that Russia is increasing the number of its deployed nuclear weapons under New START and massively modernizing its nuclear arsenal, including building new nuclear warhead designs. In comparison, the newest nuclear weapons in the U.S. arsenal are built based on designs from the 1970s. The reality is that nuclear deterrence remains extremely relevant in the current world and the United States has not been serious in thinking about its deterrent for some time.

The Independent Review identified a significant gap between the soldiers who operate the nuclear system and the leadership as one of the core problems of forces that operate U.S. nuclear weapons. The report emphasizes that the issue needs “to be addressed quickly and effectively.”

The problem starts in the While House and its dedication to nuclear disarmament ideology. The next secretary of defense will have to deal with the world as it is, not as the president imagines it. A strong nuclear deterrent remains a cornerstone of a sound U.S. nuclear weapons policy and deserves an attention as such.