For decades no one could enter or leave Elektrostal without the permission of the Soviet security services. After World War II, the city (whose name means “electric steel”) had been chosen as a uranium-development site. Only 36 miles east of Moscow, Elektrostal became a closely controlled hub in the Soviet nuclear weapons program, and a kind of prison for scientists working on the project and their families.

Today, the situation is very different. Elektrostal lost its status as a closed city in 1991. The factories still produce nuclear fuel, but residents are free to come and go as they please, and factory safeguards have slipped dramatically.

The looser standards are on display at the Machine Building Plant on Karl Marx Street. The Plant is one of Elektrostal’s main factories, a major supplier for the nation’s fuel-rod industry. It is a crumbling, red-brick building surrounded by walls topped with rusted barbed wire. When I visited on a chilly October morning, I was met by the menacing glare of a tan-and-brown dog, who was hardly an obstacle to anyone determined to enter the building.

• • •

With the collapse of the Soviet Union in 1991, serious concerns emerged about “loose nukes”—the possibility that nuclear weapons or materials could be stolen by criminals or terrorists. In response Congress created the Nunn-Lugar Cooperative Threats Reduction Program (1992), an ambitious attempt to provide human and financial resources to the former Soviet republics, which suddenly found themselves with large stockpiles of nuclear material. Despite these early efforts, more than a thousand incidents of nuclear smuggling have occurred since 1993, according to the United Nations’ International Atomic Energy Agency. A number of these thefts have occurred at the Machine Building Plant. In 2001 a group including two former Russian Ministry of Interior police officers tried to sell a kilogram of low-enriched uranium stolen from the Plant, and in 2006 a Plant supervisor sold five kilograms of uranium fuel pellets to undercover police officers.

After Nunn-Lugar, the loose-nukes issue languished for nearly twenty years. Now President Obama has taken the first serious steps to refocus attention on it. This April’s Global Nuclear Security Summit concentrated on efforts to lock down nuclear stockpiles, and achieved some achieved some important victories. Ukrainian President Viktor Yanukovych announced that his country would dispose of all of its highly enriched uranium, eliminating the possibility that terrorists will gain access to the material. Dozens of leaders made other specific commitments.

Officials in both the United States and Russia still approach the issue of nuclear arms as if only a blink away from a showdown.

Obama’s efforts on nuclear weapons have not been confined to loose nukes. He and Russian President Dmitri Medvedev signed a new Strategic Arms Reduction Treaty (START) that promises to cut the number of nuclear warheads in Russia and in the United States. And the Nuclear Non-proliferation Treaty will be reviewed in May at the United Nations.

While the proximate concern is nuclear terrorism—Obama has warned that terrorists are “determined to buy, build, or steal” a nuclear weapon—the larger goal is “global zero,” a world without nuclear weapons. In pursuit of that goal, Obama has generated a level of activity around the nuclear threat that is without recent precedent.

Still, the obstacles to achieving these ambitious aims are considerable. In Washington many officials, guided by unilateralist ideas about national security, cling to a robust U.S. arsenal. And while Obama and Medvedev have reached an agreement on a new START, Republicans may hold up its ratification when the treaty is submitted to the Senate later this year. The administration itself is filled with hawkish holdovers from the Bush era and new blood who support the status quo either because they think it is sound, or because they prefer to concentrate on domestic issues.

For their part, Russian officials feel manipulated and betrayed by their U.S. counterparts, regardless of who is in the White House. Obama and Medvedev may have joked around during the START signing in Prague—highlighting their “personal chemistry,” as Medvedev described it—but their warm feelings are not shared by many of their colleagues. Prime Minister Vladimir Putin is famously hostile toward the United States and has stalled negotiations over nuclear arms. Following his example, many high-ranking Russian officials have been looking quietly for ways to undermine the new START.

Yet the overarching impediment to improved nuclear security and progress in disarmament is neither congressional cost-benefit analysis nor the stubbornness of Russian leaders, but rather the heavy burden of history.

Officials in both countries approach the issue of nuclear arms as if only a blink away from a showdown. Still frozen in a Cold War mindset, Russian officials believe that maintaining a strong arsenal is of paramount importance and that no nation that is serious about defense would jettison its nuclear weapons. They view the notion of sweeping nuclear disarmament as a fantasy, “a concern only of rich Americans,” explains Mikhail Tsypkin, a Moscow native who teaches at the Naval Postgraduate School in Monterey, California.

Russians are certain that global zero will never happen. They argue that even if Americans agreed to get rid of their own nuclear warheads, other countries would balk. After all, in a nuclear weapons-free world, the United States would remain the most powerful nation. Russians are also more relaxed than Americans about the possibility of a nuclearized Iran. “It’s like what they used to say in the gulag,” Tsypkin says. “‘You die today, I die tomorrow.’”

• • •

With Russian disco blaring in the cafeteria, a blocky Soviet-era design, and a rotary phone in one of the halls, the Center for Arms Control Studies at the Moscow Institute of Physics and Technology has a distinctively ’70s feel. An aura of the Cold War permeates the sprawling campus.

“It was spying, to some extent,” the Center’s director, Anatoli Diakov, tells me. His pale blue eyes dart surreptitiously around the room as he shows me how American inspectors verifying compliance with START act during their visits to Russian nuclear facilities. He is convinced they are gathering intelligence on the nation’s defense program.

Diakov may seem overly suspicious about the U.S. officials who visit Russia, but he has his reasons. Tensions between the countries have led officials at the Kremlin to crack down on its own arms-control researchers. A few years ago, one of Diakov’s colleagues, a researcher named Igor Sutyagin, came under suspicion of espionage. Sutyagin was working in Moscow for a British consulting group, and prosecutors claimed, not improbably, that the company was a front for the British intelligence services and that he had been working for the CIA.

Agents with the Federal Security Service (or FSB), the successor to the KGB, questioned Sutyagin and examined colleagues’ files. They confiscated computers from the Center. During their investigation agents discovered $30,000 at Sutyagin’s house. His friends said he was foolish to keep so much cash at home, since it raised the suspicions of the FSB, but everyone who knew him was adamant about one thing: he did not have access to classified information. Whatever he may have given to the British consulting company, or even to the CIA, had been culled from open sources. In other words, say his friends and colleagues, he did not reveal state secrets. For the FSB agents, that was beside the point. An arms-control researcher could copy down a timetable at a Moscow train station and give it to the Americans, one of Sutyagin’s colleagues explained, and he would be arrested for espionage.

Sutyagin was found guilty of treason in 2004 and sentenced to fifteen years hard labor. His arrest had a chilling effect on Russian researchers. Many operate in secret offices tucked away around Moscow and remain extremely careful about what they publish. They use extensive footnotes in their articles and books in order to demonstrate that they have relied on open sources for their material and cannot be accused of revealing state secrets.

At the Institute of World Economy and International Relations, Alexander Pikayev writes reports for the Kremlin in a small room on the twentieth floor. The elevator stops at the eighteenth floor, and he walks up two flights. The office building was designed during the Cold War. These days, his door remains locked at all times.

Nearly twenty years after the Cold War ended, he is as zealous as his predecessors about keeping his papers safe and equally cautious when speaking with Americans. He is wary of the Obama administration, and points out ways that Americans continue to upgrade their nuclear arsenal and hinder the progress of arms control. Like researchers and officials throughout Moscow, though, Pikayev also has misgivings about the Kremlin. The arrest of Sutyagin, he explains, was “politically motivated” and was “part of closing doors and re-establishing state authority over non-governmental organizations.”

The officials in Moscow are paranoid and brutal. “The bottom line is that there are major, unresolved issues after the breakup of the Soviet Union,” Georgetown political scientist and former National Intelligence Council officer Angela E. Stent says.

At the global level, the Russians are the weaker opponents. They have fewer weapons and less money than the Americans, and they control a less formidable conventional force. When it comes to disarmament, the officials in Washington hold the cards, and they are reluctant to give them up. Neither side has a monopoly on obstructionism, nor, as Stent points out, on anxiety. “There is a lot of mutual suspicion,” she says, “a lot of concern about other’s intentions.”

The need for sharing, however, is great. What if terrorists blew up a dirty bomb in an American city, and scientists traced the material back to Russia? As the situation currently stands, the scientists would have no way of knowing whether the material had been sold or stolen. What would Obama do?

• • •

The new START has been heralded as a milestone in nuclear diplomacy. In an op-ed, Senator John Kerry wrote, “this treaty will make our world safer.” A New York Times editorial echoed those sentiments, calling it an “important [step] to make the world safer.” And a Wall Street Journal reporter described it as “the most significant arms-control treaty in nearly two decades.” Even before the signing, The Washington Post, Associated Press, and other news organizations breathlessly informed their readers that once the treaty was ratified, the nuclear arsenals of both Russia and the United States would be reduced by a third.

In fact, the agreement will make a much smaller difference. It will restrict both nations to 1,550 deployed strategic warheads, which means a real reduction. But both countries have hundreds of additional “non-strategic” nuclear weapons, designed for use against a modest nearby target rather than an entire distant city. Although their yields make them less destructive, these weapons still are terribly lethal. “In the real world, a nuclear weapon is a nuclear weapon,” says Pierce Corden, a former State Department office director in the Arms Control Bureau. “Just like a rose is a rose.”

According to Hans Kristensen of the Federation of American Scientists (FAS), when all warheads are taken into account, the new START reduces Russia’s nuclear inventory by a mere 8 percent and the United States’s by even less—5 percent.

The strongest resistance to Obama’s plans for global zero comes from defense leaders who are hard-wired to push for bigger and better weapons.

Arms-control advocates hope for another round of deeper cuts, but that seems unlikely, at least in the near future, since a hollowed-out State Department, bureaucratic inertia, and recalcitrance at the Pentagon make it hard to get things done. One key office, the Bureau of International Security and Nonproliferation at the State Department, lacks a permanent director, and until recently few people working on the issue seemed charged up. Daryl Kimball, Executive Director of the Arms Control Association, recalls the “lack of passion” when a State Department official spoke about the president’s agenda. “He was ticking off things on a to-do list. It wasn’t, ‘We need to act now.’” Part of the problem, Kimball says, is that arms control became “a policy backwater” during the Bush years. “The Bush administration gutted [arms-control] offices, transferred people to other places and took away a lot of State Department arms-control expertise.”

Obama and his allies are not only working against weakened federal agencies, but also against skeptical officials. More than 140 political appointments under Bush were converted into career positions, according to a May 2006 report from the Government Accountability Office. These individuals remained in their jobs after Bush left the White House. Whether they are working specifically on arms control or on other issues, their presence has had an impact on the federal agencies and slowed down the process toward a nuclear agreement. Many mid- and upper-level officials at the Department of Energy, the Department of Defense, and other federal agencies have spent their careers pursuing an upgrade of the nation’s nuclear arsenal.

At the Department of Energy’s National Nuclear Security Administration (NNSA), for example, officials argued for years on behalf of the so-called Reliable Replacement Warhead—a new-and-improved version of the old model—until Congress finally turned down their requests. The head of the NNSA, Tom D’Agostino, is a holdover from the Bush administration who, in the past, was among those pushing for the Reliable Replacement Warhead. He has recently pledged his loyalty to the new boss, “but you know how it is,” FAS’s Kristensen says. “I don’t know if he’s going to pursue the same [old] agenda quietly.”

The strongest resistance to Obama’s plans for global zero comes from a group of defense leaders who are hard-wired to push for bigger and better weapons. Defense Secretary Robert Gates was a supporter of the Reliable Replacement Warhead, and, as Ron Rosenbaum reported in Slate last August, some top military officials have also attempted to impede progress on disarmament. Air Force General Kevin P. Chilton, who took over United States Strategic Command in October 2007 and remains in that job, “comes close to insubordination by saying, ‘We’re going to have nuclear weapons in this country for the next one hundred years,’” Kristensen suggests. “I have heard him say, ‘For as long as the United States exists.’”

Public statements such as these, made by prominent military officials, undermine Obama’s agenda. In his Nuclear Posture Review—the president’s official position on nuclear policy—Obama placed additional limits on when the United States could use nuclear weapons against another nation and renounced the development of new weapons.

Perhaps in an attempt to win the support of his opponents, Obama has crafted a policy that leaves plenty of room for the United States to launch a nuclear attack. Under the Obama nuclear posture, the United States will not launch a strike against a country that does not possess nuclear weapons, but it reserves the right to do so—under certain circumstances—against Iran and Syria, neither of which are known to have such weapons at this time. “Are we committing to a continuation of the nuclear era?” Kristensen asks, “or are we taking concrete steps to the elimination of nuclear weapons?”

It is a question that many have been asking, with increasing impatience, since the end of the Cold War. However, the culture of arms control, in Washington and in Moscow, is dominated by people who seem unconcerned—cold warriors who live in fear of a nuclear attack and are devoted to stockpiling and modernizing warheads. Their anxiety puts arms-control researchers in Moscow behind locked doors and imposes significant hurdles to attempts at disarmament and control of nuclear materials.

Yet the biggest threat to both nations comes not from each other, but from a rogue element outside the arms-control arena. Whether the threat originates with al Qaeda or a loosely organized terrorist group, the individuals behind it can exploit the discord between the two largest nuclear powers. Meanwhile, vast repositories of highly enriched uranium and other dangerous material—roughly 1,850 metric tons of the stuff, enough to make tens of thousands of bombs—are lying around the world in places like the Machine Building Plant in Elektrostal, guarded by nothing more than a tan-and-brown dog chained to a wall.