There is never a good time to lose a man of the caliber, character, and vision of James R. Schlesinger. As it happens, however, the nation he loved and served for decades with such distinction is in particular need of his unique leadership at this juncture. His passing last week is a double blow.

Dr. Schlesinger was a Renaissance man with a brilliant mind deeply steeped in the study of letters, science, finance and budgetary matters, governmental policy, and the arts. He devoted most of his professional career to the study and practice of national security, starting with stints at the RAND Corporation and then the Bureau of the Budget under President Nixon.

It was Nixon who gave Jim Schlesinger his first official portfolio in the field that would define his long and distinguished career: nuclear energy and deterrence. He served as chairman of the Atomic Energy Committee, the institution that nurtured and presided over the nation’s formative years as a nuclear power. In a succession of other senior positions – including those of Director of Central Intelligence and Secretary of Defense under Republican presidents and as Secretary of Energy under a Democratic one – he brought to his posts a virtually unrivaled mastery of what it takes to have and maintain safe, reliable, and credible deterrent forces.

Dr. Schlesinger’s long experience told him that deterrence was a dynamic proposition, not a static one. He recognized the need for U.S. forces to be operated, maintained, and modernized by competent military and civilian personnel. And he understood that, to have the necessary dissuasive effect, nuclear arsenals need to be tailored to the evolving capabilities and strategic calculations of potential adversaries.

For these reasons, Jim Schlesinger steadfastly opposed during his time in the Carter administration and subsequently as an elder statesman the idea of a Comprehensive Test Ban aimed at prohibiting the underground testing needed to develop and improve America’s nuclear forces.

I had the privilege of getting to know and work closely with Dr. Schlesinger in the run-up to and during the U.S. Senate’s debate in 1999 about whether to advise and consent to a Clinton-era treaty imposing such a test ban. His articulate and authoritative critique of that accord, informed by unsurpassed personal experience with every aspect of the “nuclear enterprise” – weapons design, production, testing, deployment, and retirement – helped Senator Jon Kyl (R-AZ) secure an actual majority of the Senate for rejection of the Comprehensive Test Ban Treaty, well over the 34 votes required for that purpose.

Sadly, in the years since James Schlesinger’s tenure as Secretary of Energy came to an end in 1979, there have been few in senior positions with his acumen about nuclear deterrence, and fewer still with his dedication to preserve it. As a result, with the notable exception of the Reagan years – when much of today’s arsenal was put in place – the last thirty-five years have seen, at best, benign and, at worst, malign neglect of the nation’s nuclear forces and the industrial base required to sustain them.

Over these years, it often fell to Dr. Schlesinger to warn of the dangers of such behavior. Notably, in 2009, he co-chaired with another former Secretary of Defense, William Perry, a blue-ribbon commission on strategic forces that urged course corrections in myriad respects. These included the need for modernization of the aging nuclear stockpile and its associated weapons manufacturing and maintenance complex.

Unfortunately, President Obama has taken a very different approach. He has established as national policy the goal of ridding the world of nuclear weapons. In practice, he has pursued this objective by encouraging the atrophying of America’s forces, reducing their numbers – either unilaterally or on the basis of an unverifiable New START arms control deal – and allowing the dissipation of the talent and infrastructure required to preserve the deterrent’s viability.

In recent weeks, the folly of such official policies and the wisdom of Jim Schlesinger’s contrary counsel has been born out. Under the umbrella of increasingly modern and threatening strategic nuclear forces, Russia’s Vladimir Putin has been engaging in unchecked aggression against a now nuclear-free Ukraine. Ditto China against the Philippines, Japan, and others in the Western Pacific. Meanwhile, North Korea, Iran, and other threatening powers are demonstrating that only the United States is engaged in nuclear disarmament.

At the same time, the co-chairmen of a successor to the Perry-Schlesinger Commission, former Navy Admiral Richard Meis and former Lockheed Martin chairman Norman Augustine, provided an ominous picture of “systemic disorders” that imperil the future viability of the deterrent last week before Congress. Mr. Augustine warned, “[S]ustained national commitment and focus on the entirety of the mission and the [nuclear] enterprise charged with its execution has been lacking since the end of the Cold War, as evidenced by the condition in which the enterprise finds itself today. The Department of Energy and the National Nuclear Security Administration have failed to act with a sense of urgency at obvious signs of decline in key areas.”

Meanwhile, Air Force Secretary Deborah Lee James reported on March 27th the findings of an internal review of a series of personnel problems involving officers responsible for intercontinental ballistic missiles in Montana. It raises questions about morale and leadership in the ranks – but not about the negative impact being had on both as a result of the Commander-in-Chief’s evident disdain for these officers’ vital mission.

In fact, we are facing a systemic crisis of leadership with regard to national security more generally, not just with respect to nuclear deterrence. This is a moment when Jim Schlesinger’s formidable intellect, his willingness to do the right thing – no matter how “politically incorrect” it may be – and his commitment to speaking truth to power, especially with regard to maintaining our nuclear forces, are more needed than ever. They are likely to be sorely missed.

Frank J. Gaffney, Jr. formerly acted as an Assistant Secretary of Defense under President Reagan. He is President of the Center for Security Policy (www.SecureFreedom.org), a columnist for Breitbart News Network and host of the nationally syndicated program, Secure Freedom Radio.