As you've never seen them before: The stories that defined our year

The problem from hell

A brutal civil war is carving a country up five ways and giving rise to an entirely new phenomenon: the terrorist organization that thinks it's a state. American leaders called Bosnia the "problem from hell" in the 1990s, but the description is even more apt for Syria today. The war has sucked in the United States, its allies and Russia; spewed out jihadis who have carried out terror attacks in the West; and created the biggest refugee crisis in generations. Half of all Syrians have been killed or have fled their homes. The country's neighbors are hosting 4 million refugees, while Europe is thinking about fundamental changes to its open internal borders after half a million Syrians crossed the Mediterranean this year -- not including an estimated 1,800 or more who drowned trying to make the journey. Two-year-old Aylan Kurdi came to symbolize the entire tragedy when his tiny body washed up on a Turkish shore in September. Meanwhile, the United States, Russia, France and Britain are all bombing, but ISIS is showing no sign it's going anywhere.
-- Data editor Richard Allen Greene

    #NousSommesParis

    The terrorist attacks on Paris in January and in November were horrific reminders that Europe remains vulnerable to the upheavals wracking the Middle East and to the growing appeal of ISIS among radicalized young men. One of the January gunmen had pledged allegiance to ISIS leader Abu Bakr al Baghdadi days earlier. Several of those involved in the November attacks had spent time in Syria training with ISIS. There were other alarming lessons from these attacks: Intelligence agencies are unable to track many would-be jihadists who have traveled to and from Syria; cooperation between European security services remains patchy; and terrorists can acquire high-powered weapons inside Europe with ease. The series of attacks in November was more stunning because of the organization and resources required and the ability of at least two suspects to vanish afterward. And both attacks were a reminder of an ominously familiar pattern: Many of those involved were young men without work, some of whom had spent time in prison for petty crime, had dabbled in drugs and had difficult family backgrounds: marginalized drifters in search of "redemption."
    The gun attacks in Copenhagen, Denmark, in February, whose targets included a synagogue, bore many of the same traits as Amedy Coulibaly's Paris attack a month earlier. Omar Abdel Hamid el-Hussein had also spent time in jail and had also pledged allegiance to ISIS. The metastasis of ISIS in 2015 -- beyond Iraq and Syria -- was evident in terror attacks in Tunisia and Beirut. But almost as if warning the world not to forget its existence, al Qaeda hit a hotel in the Malian capital of Bamako, killing 21 people, just days after the Paris attacks. A sign perhaps that it and ISIS may seek to outbid each other in inflicting acts of terror on the wider world.
    -- CNN contributor Tim Lister

    Putin the czar?

    Vladimir Putin sits atop the world's biggest country, with virtually unchecked power and a proven willingness to wield it, first in Ukraine and now in Syria. His ordering of massive airstrikes against rebels in Syria this year has significantly bolstered the flagging government of President Bashar al-Assad there, which appeared to have been losing the war. The bombing also sends the West a powerful message: Putin will not tolerate the loss of a key Middle Eastern ally and will fight to keep Russian influence in the region. Putin's rhetoric about fighting ISIS and international terrorism has also won the Russian leader a return to the top table of international diplomacy, ending his isolation after the annexation of Crimea last year. He's also immensely popular among Russians, who see him as a decisive leader, taking strong action against international terrorism and forcing the West -- Russia's old Cold War rival -- to take Moscow seriously once again.
    -- Senior international correspondent Matthew Chance

    Nepal shaken

    I met Maya Gurung in a hospital after the April earthquake in Nepal and knew her future in an impoverished village would be bleak. She was 10, and her left leg had been amputated. But sometimes, even amid tragedy, life takes twists so fortuitous that they seem predetermined. Several weeks after I met Maya, Jwalant Gurung -- no relation -- spotted her father carrying her on his back and decided to help. Gurung, who makes his living organizing tours and treks in Nepal, had Maya fitted with a prosthesis and invited her to stay with him in Kathmandu so she could go to school. Now, as the year comes to a close, I think about Nepal and how the story of the earthquake resonated so much with us. The numbers alone were horrific: Nearly 9,000 people dead, around 600,000 houses flattened. But it was more than that. Perhaps it was because Nepal is a nation of enormous majesty, nestled amid the tallest Himalayan peaks in the world that draw so many foreigners. We received so many responses to a story about Eric Poppleton, a California photographer who returned to Everest Base Camp to retrieve the body of a friend killed with 18 others in a quake-triggered avalanche. And another good Samaritan, Yasmine Habash of Alaska, flew to shattered Langtang to search for her missing mother. It seemed that many of us had some intimate connection to the mountain kingdom through our fascination with Mount Everest or Buddhism or ancient culture. Nepal was a land far away, and yet, it felt close.
    -- Reporter Moni Basu

    Germanwings crash

    The Germanwings disaster affected people on many levels. It hit close to home for anyone who regularly gets on airplanes. It involved a very fundamental fear: "Can I trust the person flying this plane?" And it involved one of the safest airlines in the world missing several red flags and allowing a person with a serious mental disorder to pilot an aircraft. In the short term, the disaster made many people emotional: Seeing the debris on the side of the mountain after the plane hit the Alps at around 435 mph (700 kph), and watching whole communities and families suffer after their loved ones had been killed by a selfish man with depression. There will also be long-term implications. The monitoring of pilots' mental health will be reformed. Many airlines have changed their rules on the number of people in the cockpit. The disaster gripped us for weeks because of its emotional factors, but also because of the fundamental importance to an industry so many rely on to travel for work and vacations.
    -- Senior international correspondent Frederik Pleitgen

    Volkswagen chokes

    Less than two months after taking Toyota's crown as the world's biggest automaker, Volkswagen was brought crashing back to earth by one of the biggest corporate scandals of all time. The company was forced to admit that it was deliberately cheating pollution tests, misleading regulators, shareholders and customers about some of its cars' emission levels. Volkswagen, one of Germany's manufacturing icons, has said it will cost billions to fix up to 11 million vehicles affected. It has suspended sales of some new models in the United States, replaced its CEO and slashed spending plans. Legal action is likely to drag on for years, as car owners, dealers and investors pursue compensation claims through the courts. The final bill will be huge.
    -- CNNMoney international editor Mark Thompson

    Fragile China

    What a roller-coaster year for China! Its stock market crash made global investors so nervous that they sent markets everywhere into the red. People were losing money left and right -- folks as far away as Norway saw their retirement savings shrink. Markets may have stumbled into recovery since, but the fears that triggered the crash simply aren't going away. Over recent decades, China rose quickly as an industrial powerhouse to become the world's second-largest economy, consuming lots of raw materials to build roads, bridges, factories and skyscrapers. But now, with the country posting its slowest growth since the financial crisis, construction is faltering and demand is waning for iron ore, copper, steel and lead. Global commodities markets, and the countries that depend on them, are taking a big hit. A slowing economy also means less money in China's pockets, which is bad news for major trade partners like the United States and Europe, which export to China.
    -- CNNMoney reporter Sophia Yan

    Happy nerds

    This year has given space nerds of the world much to buzz about. From discovering flowing water on Mars, to understanding how the red planet's ancient oceans disappeared, to New Horizons' Pluto flyby, the complexity and diversity of our solar system have never been better understood or more clearly transmitted to us Earthlings. Yes, these discoveries excite the globe, inspire a new generation of scientists and engineers, and reignite our fervor for space exploration. But perhaps even more exciting is that, with every new discovery, every successful mission, we gain a better understanding of our origin. We learn where to best probe our solar system for microbial life -- a.k.a. aliens -- and, ultimately, how we might be able to extend life beyond the boundaries of Earth and colonize other planets.
    -- Correspondent Rachel Crane

    Unsporting behavior

    It's been an ugly year for the beautiful game. Soccer hit the news, but little of the talk surrounded people actually playing soccer. Instead, it centered on men in suits, men with badges and allegations of widespread corruption. There were arrests, guilty pleas and tens of millions of dollars in fines. The current frontrunner in this sporting race to the bottom is Sepp Blatter. The man in charge of world football hasn't been charged with a crime, but he is banned from soccer-related activity. Luckily, 2016 will see the return of that bastion of integrity, that temple of fair play and enduring monument to human spirit -- the Olympic Games. But there may be fewer Russian Olympians than you'd expect in Rio de Janeiro. The country's track and field athletes are banned from international competition after a World Anti-Doping Agency report that alleged a "deeply rooted culture of cheating at all levels" within Russian athletics. With a FIFA presidential election and the prospect of more revelations from WADA, next year promises to be just as memorable as this one, but for all of the wrong reasons.
    -- Sports writer Tom McGowan

    That dress

    Whether you thought it was #blueandblack (like Taylor Swift) or #whiteandgold (like Kim Kardashian), with more than 3 million mentions on Twitter and dozens of news reports, you inevitably saw it and had an opinion about the color. Even once the original debate was settled, it was the meme that kept on giving. The company that made the dress confirmed it was, in fact, blue and black. (Yes! Victory for this writer, at least.) But that just spurred more discussion about why we were all seeing it in different ways, and why we were all so sure that we were right and the other side was wrong. Scientists said it has to do with the way light enters our eyes, although that didn't stop some people from being convinced that half their friends and co-workers were suddenly colorblind. And it launched a fun few weeks of an Internet optical illusion obsession. Here are a few of our favorites if you're in the mood for a trip.
    -- Social media producer Rachel Rodriguez