As a former covert CIA operative, specializing in counter-proliferation, I still believe that the spread of nuclear weapons and the risk of their use is the greatest existential threat we face. Twenty-six years after the end of the Cold War, the world still has more than 15,000 nuclear weapons. Whatever other issues people care about — poverty, the environment, inequality and so many others — if we don’t get this one right, and soon, nothing else will matter.

We are at a crossroads on this issue and the decisions we make over the next 10 years will set us on a course either toward the elimination of all nuclear weapons or toward expanding arsenals and proliferation.

As a former covert CIA operative, specializing in counter-proliferation, I still believe that the spread of nuclear weapons and the risk of their use is the greatest existential threat we […]

There are some disturbing trends.

All of the nuclear countries are investing heavily, or planning to do so, in modernizing their forces and/or expanding their arsenals. President Obama is proposing a massive overhaul of the U.S. nuclear arsenal that the Congressional Budget Office (CBO) estimates will cost $1 trillion over the next 30 years. Russia has already begun a major upgrade of its arsenal. China is ramping up each leg of its nuclear triad, India is close to having a full nuclear triad with the addition of a nuclear submarine to its forces, and North Korea continues to develop its nuclear capability. Perhaps most worrisome is Pakistan, which has the fastest-growing nuclear arsenal and is plagued by persistent political instability and extremist elements.

In addition to developing new types of weapons, nuclear weapons countries also appear to be taking steps toward establishing the dangerous nuclear high-alert posture that the United States and Soviet Union adopted during the Cold War (and still maintain) — shortening the decision time for launch and increasing the risk that nuclear weapons will be used in conflict, by accident or through unauthorized launch.

Longstanding regional conflicts involving nuclear-armed countries remain unresolved and tensions high, including on the South Asian Peninsula, the Korean Peninsula and the Middle East. Relations between Russia and the West have spiraled dangerously downward; Russia has even threatened to use nuclear force to defend its annexation of Crimea.

Meanwhile, terrorists are working to get their hands on the bomb. This danger has risen as states have failed and ungoverned zones have spread, especially in the Middle East and Africa. In the last two decades there have been dozens of incidents of nuclear explosive materials being lost or stolen. The so-called “Islamic State” group has already seized low-grade nuclear material from a facility in Mosul.

These are very difficult challenges. But there are also significant factors that could provide opportunities for progress.

A final agreement with Iran would verifiably prevent it from developing a nuclear bomb. It would negate a long-standing leading argument of opponents to Global Zero— that Iran and countries like it would never agree to forgo nuclear weapons. And it provides a model — multilateral negotiations and intrusive verification — for pursuing global reductions in nuclear arsenals.

Budgeting pressures and austerity measures in key countries are forcing governments and militaries to rethink the value of nuclear weapons. This could call into question current plans for large-scale investments in nuclear forces — and even plans to maintain arsenals at their current sizes. If forced to choose, military leaders would presumably opt for conventional weapons they actually use over nuclear weapons, which they don’t. As U.S. Secretary of Defense Ash Carter said recently regarding budget pressures, “I will not send our troops into a fight with outdated equipment, inadequate readiness, or ineffective doctrine. But everything else is on the table — including parts of our budget that have long been considered inviolate.”

So what must be done to leverage these opportunities, overcome the obstacles and move away from a future of proliferation and increasing nuclear risks toward the elimination of nuclear weapons worldwide?

In the near-term, we need to get the Iran deal done — a verifiable, negotiated deal is by far our best option for preventing Iran from getting the bomb. And President Obama must abandon plans to lock us into a $1 trillion nuclear arsenal for decades to come and instead refocus his efforts on finding ways to move toward the reduction of nuclear weapons worldwide.

One promising option involves “de-alerting” measures by nuclear countries — practical steps to increase warning and decision time. This could lead to a multilateral agreement requiring all nuclear weapons countries to refrain from actively deploying nuclear weapons. This would immediately and dramatically reduce the risk that nuclear weapons will be used. It would also engage nuclear weapons countries — beyond the United States and Russia — in the process of arms control for the first time, laying the groundwork for multilateral negotiations on global nuclear arms reductions and elimination.

Global Zero is currently spearheading an effort to enlist nuclear countries to adopt de-alerting measures, led by its Commission on Nuclear Risk Reduction — an international group of former military commanders, political leaders and diplomats chaired by retired U.S. Vice Chairman of the Joint Chiefs of Staff General James E. Cartwright.

At the same time, we need to focus on building a grassroots movement for the elimination of nuclear weapons. More than anything, we will need public pressure to get to zero.

Global Zero has been systematically laying the groundwork for such a movement for several years, educating and training students and establishing hundreds of campus chapters worldwide, assembling a first-rate team of campaigners and testing innovative new approaches to grassroots organizing. All of this is now being dramatically scaled up with the launch of the Global Zero Action Corps — an exciting new initiative to build a large-scale and sustained global grassroots movement.

Building such a movement with the power to push our political leaders toward zero will take years of dedicated, painstaking organizing work. There are no shortcuts. Unless we are willing to see a nuclear weapon used in the next 10 years, we all need to get involved and do our part.