The nuclear weapons news of late has been alarming. David Sanger reported in "The New York Times" on January 9 that Iran's top nuclear official had announced his country was near initiating uranium enrichment at a new plant. And the recent leadership change in North Korea means added uncertainty about one of the world's most unpredictable nuclear weapons states. Both developments mean the danger is rising that nuclear weapons or the means to make them will spread in this year.

The ominous news brings to mind a comment that Robert M. Gates made a few years ago while working as President Obama's Secretary of Defense. "If you were to ask most of the leaders of the last administration or the current administration what might keep them awake at night," he told me, "it's the prospect of a [nuclear] weapon or nuclear material falling into the hands of Al Qaeda or some other extremists."

I was interviewing Gates for a book about nuclear threats. The book, "The Partnership: Five Cold Warriors and Their Quest to Ban the Bomb," [Harper, $29.99] examines the acute state of nuclear dangers today, including the spread of nuclear materials and technology to unstable nations like Pakistan, North Korea and Iran. If a terror group like Al Qaeda is ever going to get its hands on a nuclear weapon, or more likely the fissile material needed to make one, the source is likely to be one of those three nations. North Korea and Pakistan have a frightening history of exporting nuclear weapons technology. Iran may be next.

Despite the denials of Iranian leaders, Tehran seems well on the way to building its first nuclear weapon. Iran already has enough enriched uranium to make several warheads once the uranium is raised to a higher level of enrichment. The enrichment process can move very quickly from a low level to high, bomb-grade levels. Some upgrading of known Iranian enrichment facilities are required to get there, and these changes would be visible to the outside world. Still, Iran may well have hidden enrichment programs already cranking out highly enriched uranium. If it does move openly to higher enrichment, Israel and the United States will be tempted to attack Iran's nuclear installations.

A simple but powerful nuclear weapon can be fabricated with just a small amount of highly enriched uranium. The hardest part of making a uranium bomb is producing highly enriched uranium, something that requires advanced, industrial-scale technologies beyond the reach of a terror group. But with just 60 pounds of highly enriched uranium, a small, savvy group of engineers with some basic laboratory equipment could construct a fission bomb in a garage. The bomb mechanism is so straightforward that the United States did not bother to test a uranium weapon before dropping one over Hiroshima in 1945. And it is not wildly improbable to imagine Iran giving highly enriched uranium to a terror group.

The continuation of the Kim dynasty in North Korea - now in its third generation with the recent installation of Kim Jong-un as the new supreme leader - does not augur well for more responsible behavior by North Korea. With its active nuclear weapons program, hunger for hard currency and record of selling nuclear weapons goods to Libya and Syria, North Korea is one of the most dangerous nations on earth.

While North Korea is unlikely to sell a nuclear weapon to a terror group, it could provide the materials and knowhow to make a crude but powerful bomb. The United States, for all its intelligence-gathering hardware like spy satellites, does not know a great deal about the North Korean program. Washington was surprised to learn in 2010 that North Korea had constructed a uranium enrichment plant outfitted with the latest centrifuge technology. News about the existence of the plant came from a group of American scholars who were shown the facility during a visit to the North Korean nuclear complex at Yongbyon.

The plant is not a problem if it is producing low enriched uranium to fuel a small, light water reactor. But the plant could be used to produce highly enriched uranium. The rapid construction of the plant - it was built in just 18 months - suggested that the North Koreans might have honed their techniques at another enrichment facility, as yet undetected by the United States.

I recently asked my Stanford colleague Sig Hecker, one of the scholars who visited the enrichment plant in 2010, to outline what to watch for in the North Korean weapons program in coming weeks to determine if the new leadership is planning any change in nuclear policy and/or operations. Sig served as director of the Los Alamos National Laboratory 1986-1997. He has been a frequent visitor to North Korea, one of the few Americans to get a first-hand look at the North Korean nuclear program.

His response:

I believe that there will be a period of quiet on the diplomatic front, both for mourning and to rethink strategy. Just before Kim Jong-il died, American and North Korean diplomats came close to an agreement of American food aid in return for some concessions on the nuclear program (some reports indicated that Pyongyang would stop enrichment - but I have yet to hear official confirmation from the UnitedStates - and we never may). What to look for is to see when North Korean diplomats are ready to re-engage with Americans in quiet bilateral talks, mostlikely in China.

On the technical front: I would expect "normal operations" at Yongbyon. That means they will continue with the experimental light water reactor construction- although little will be seen from overheads because it is winter time. Much of the interior components will be fabricated in shops. I also expect them to continue with operations of the centrifuge enrichment facility - either to make more low enriched uranium for reactor fuel or to get the facility to operate fully (which it may not have been when we visited). Both of these operations will continue regardless of which way Pyongyang eventually decides to go with the nuclear program. I don't see any reason why they would cut back on these operations now.

As for potential provocative actions - they could prepare for another nuclear test -- but that is highly unlikely, if for no other reason than it is winter. Their tests occurred in October 2006 and May 2009. Nevertheless, the third test tunnel appears to have been dug some time ago (South Korean news reports and overhead imagery) and one should watch closely for activity at the test site (particularly come spring). We should also look for potential missile tests - the new launch site on the west coast should be watched for another potential long-range missile launch. (They have had three attempts from the old launch site in the east: 1998 over Japan, 2006 a complete failure, and 2009 two out of three stagesworked.) They also have not flight-tested the Musudan road-mobile missile."

It would not surprise me if North Korea conducted another nuclear test in 2012. If Kim Jong-un is looking for a way to flex North Korean military power and remind his impoverished people that their nation matters to the rest of the world, detonating a nuclear weapon will do the trick.

Iran's nuclear program will also likely generate news and international anxiety this year. Iranian threats to attack US naval vessels in the Persian Gulf may seem self-defeating, but a military confrontation between Iran and the United States is not out of the question.

There is no greater danger to American and global security than the spread of nuclear weapons and the means to make them.

Textbook Synopsis From Cambridge University Press online:

How will we meet rising energy demands? What are our options? Are there viable long-term solutions for the future? Learn the fundamental physical, chemical and materials science at the heart of: 

• Renewable/non-renewable energy sources 
• Future transportation systems 
• Energy efficiency 
• Energy storage 

Whether you are a student taking an energy course or a newcomer to the field, this book will help you understand critical relationships between the environment, energy and sustainability. Leading experts provide comprehensive coverage of each topic, bringing together diverse subject matter by integrating theory with engaging insights. Each chapter includes helpful features to aid understanding, including a historical overview to provide context, suggested further reading and questions for discussion. Every subject is beautifully illustrated and brought to life with full color images and color-coded sections for easy browsing, making this a complete educational package. Fundamentals of Materials for Energy and Environmental Sustainability will help enable today's scientists and educate future generations.

Reducing carbon-dioxide emissions is primarily a political problem, rather than a technological one. This fact was well illustrated by the fate of the 2009 climate bill that barely passed the U.S. House of Representatives and never came up for a vote in the Senate. The House bill was already quite weak, containing many exceptions for agriculture and other industries, subsidies for nuclear power and increasingly long deadlines for action. In the Senate, both Republicans and Democrats from coal-dependent states sealed its fate. Getting past these senators is the key to achieving a major reduction in our emissions.

Technological challenges to reducing emissions exist, too. Most pressing is the need to develop the know-how to capture carbon dioxide on a large scale and store it underground. Such technology could reduce by 90 percent the emissions from coal- fired power stations. Some 500 of these facilities in the U.S. produce 36 percent of our CO2 emissions.

But these plants aren’t evenly spaced around the country. And therein may lie the key to addressing the political and technological challenges at the same time. If the federal government would invest in carbon capture and storage, it could go a long way toward persuading politicians in every state to sign on to emission reductions.

I’ll get to the specifics of the technology shortly. But first, consider how the costs of emission reduction fall hardest on certain parts of the country: A carbon tax levied on all major sources of released CO2, the approach favored by most of the environmental community, would make energy from coal-fired power plants cost more. To make a significant difference, such a tax would have to amount to $60 a ton.

Midwest Carbon Footprint

As a result, gasoline prices would rise 26 percent, and natural gas for household usage by 25 percent, nationwide. Rich and urbanized states could probably tolerate this. The West Coast, with its hydroelectric power, and the Northeast, which relies to a large extent on natural gas, could most easily absorb the associated increase in energy costs.

But the price of energy in the rural, Midwestern states would more than quadruple because of their large carbon footprint. Midwesterners get most of their electricity from coal; they drive relatively long distances to get to work, shopping and entertainment; and rural homes and buildings use more energy for heating and cooling.

One carbon-tax proposal now being considered is a “cap and dividend” plan that would send the tax revenue back to all U.S. citizens equally. But that would also favor the rich states that are less dependent on driving and coal.

It would be more helpful for the coal-dependent states if the federal government would use revenue from a carbon tax to help develop the technology for carbon capture and storage.

And that brings us to the technological challenges: No plant of any size with the capacity for CCS yet exists, but it has been demonstrated to work at small scales. Three different processes for capturing the CO2 are being tested, and scaling them up for 500-megawatt or 1,000-megawatt facilities should be possible.

For two years, the Mountaineer plant in New Haven, West Virginia, has been capturing and storing a tiny amount of its CO2 -- 2 percent of it -- but plans to build a full-scale carbon-capture plant here have been abandoned. Because Congress has dropped any idea of imposing a tax on carbon emissions, the investment doesn’t make sense.

A large plant in Edwardsport, Indiana, was being constructed with the expensive gasification process that makes it easy to add carbon-capture facilities, but it, too, has been shelved.

China may finish its large demonstration carbon-capture plant before the U.S. gets any model up to scale. Others are planned in Europe, and a small one is operating in Germany. This plant has been unable to get permission for underground storage, so it is selling some of its CO2 to soft-drink companies and venting the rest.

Subterranean Storage

Storing captured CO2 is eminently possible, too. For 15 years, the Sleipner facility in Norway has been storing 3 percent of that country’s CO2 underneath the ocean floor, with no appreciable leakage. Algeria has a similar facility, the In Salah plant, operating in the desert.

One storage strategy under consideration in the U.S. is to inject captured CO2 into huge basalt formations off both the east and west coasts. Inside the basalt, the carbon gas would gradually turn into bicarbonate of soda.

There are other ways to dispose of carbon dioxide. It has been used for enhanced oil recovery for many decades without any danger, and has been effectively stored in depleted oil reservoirs. (The gas is dangerous only in high concentration.)

It remains uncertain how much of the captured CO2 might leak during storage. Even if this were as much as 10 percent, however, it would mean that 90 percent of it would stay underground.

As CCS technology develops, it will have to be made more efficient so that it uses less energy. As it is, the capture phase is expected to require that a power plant burn 20 percent to 25 percent more coal than it otherwise would.

The technological challenges may explain why energy companies haven’t lobbied for subsidies to develop CCS. The electric-energy sector isn’t known for innovation and risk- taking. Just look at the U.S.’s outdated power grid.

But the federal government could pay for the subsidies through a tax on carbon. Such a levy would have other advantages, too: It would raise the cost of energy to reflect the damage that burning coal and oil now do to the environment, and spur the development of renewable sources.

If states with large carbon footprints can’t accept such a tax, the CCS subsidies could be paid from the general fund. The cost to build coal-fired power plants with CCS technology is estimated to be about $5 billion to $6 billion -- about the price of a single nuclear power plant. The total price for the U.S.’s 500 large plants would be $250 billion. That’s as much as the planned modernization and expansion of our missile defense system over 10 years.

But it would slash our carbon emissions by at least 20 percent. There is no other politically possible way to cut CO2 as much, and as quickly -- in a decade or two. And devastating climate change is far more likely than a missile attack.

U.S. investment in CCS technology could also induce China and Europe to follow suit. And this would allow the world time for renewable-energy technologies to mature -- to the point where we could do away with coal burning altogether.

Russia watchers in the West cannot be surprised that Vladimir Putin is on his way back to the Russian presidency. Dmitri Medvedev was always his protégé, and there was no doubt that major decisions could not be made without his approval. This includes signing the New START arms control treaty, cooperating with NATO in Afghanistan and supporting U.N. sanctions on Iran — all of which should provide reassurance that Putin’s return won’t undo the most important accomplishments of the U.S.-Russia “reset.”

Yet the relationship with the West will inevitably change. For one thing, Putin can have nothing like the rapport his protégé developed with President Obama, which was built upon the two leaders’ shared backgrounds as lawyers, their easy adoption of new technologies, and their fundamentally modern worldviews.

The Bilateral Presidential Commission which Obama and Medvedev created and charged with advancing U.S.-Russia cooperation on everything from counterterrorism to health care may suffer. The relationship as a whole is not adequately institutionalized, and depends on the personal attention of Russian officials who will likely avoid taking action without clear direction from Putin, or who may be removed altogether during the transition.

Putin’s return to the presidency will also provide fodder for Western critics bent on portraying Obama and the reset as a failure, or dismissing Putin’s Russia as merely a retread of the Soviet Union.

These critics are wrong — today’s Russia bears little resemblance to what Ronald Reagan dubbed an “evil empire” — but Putin has been far more tolerant of Soviet nostalgia than his junior partner, and his next term will surely bring a new litany of quotations about Soviet accomplishments and Russia’s glorious destiny that will turn stomachs in the West.

Although he has spent his entire career within the apparatus of state power, including two decades in the state security services, Putin is at heart a C.E.O., with a businessman’s appreciation for the bottom line. Western companies already doing business in Russia can expect continuity in their dealings with the state, and it will remain in Russia’s interest to open doors to new business with Europe and the United States. The next key milestone for expanding commercial ties will be Russia’s planned accession to the World Trade Organization, which could come as soon as December.

At home, Putin faces a looming budget crisis. As the population ages and oil and gas output plateaus the government will be unable to continue paying pensions, meeting the growing demand for medical care, or investing in dilapidated infrastructure throughout the country’s increasingly depopulated regions.

This means that while Putin will seek to preserve Russia’s current economic model, which is based on resource extraction and export, he will be forced to assimilate many of his protégé’s ideas for modernizing Russia’s research and manufacturing sectors. Medvedev’s signature initiative, the Skolkovo “city of innovation,” will likely receive continuing support from the Kremlin, although it will have little long-term impact without a thorough nationwide crackdown on corruption and red tape.

Putin’s restored power will be strongly felt in Russia’s immediate neighborhood, which he has called Moscow’s “sphere of privileged interests.” Even though Kiev has renewed Russia’s lease on the Black Sea Fleet’s Sevastopol base through 2042 and reversed nearly all of the previous government’s anti-Russian language and culture policies, Ukraine is unlikely to win a reprieve from high Russian gas prices. Putin will also continue to press Ukraine to join the Russia-dominated customs union in which Kazakhstan and Belarus already participate. He may also take advantage of Belarus’s deepening economic isolation and unrest to oust President Aleksandr Lukashenko in favor of a more reliable Kremlin ally.

Putin and Medvedev have been equally uncompromising toward Georgia. Both are openly contemptuous of Georgian President Mikheil Saakashvili, and it is unlikely that any progress on relations can occur until Georgia’s presidential transition in 2013.

Putin has good reason to continue backing NATO operations in Afghanistan to help stem the flow of drugs, weapons and Islamism into Tajikistan, Uzbekistan and Russia itself. Moreover, as China extends its economic hegemony into Central Asia, he may find America to be a welcome ally.

Putin appreciates the advantages of pragmatic partnerships and will seek to preserve the influence of traditional groupings like the U.N. Security Council and the G-8 while at the same time promoting alternatives like the Shanghai Cooperation Organization and the Brics.

The succession from Putin to Medvedev and back again was decided behind closed doors, and the formal transition of power is likely to take place with similar discipline. This should offer the West and the wider world some reassurance. Putin’s return to the presidency is far from the democratic ideal, but it is not the end of “reset.” Many ordinary Russians support him because he represents stability and continuity of the status quo and, for now, that is mostly good for Russia’s relations with the West.