(Bloomberg News) Rampaging natural catastrophes, global financial calamities, the deaths of despots and desperados, the passing of America's greatest modern technical innovator and roiling protests that shook the Arab world and occupied Wall Street -- they made 2011 a year that will be remembered for its almost unrelenting turmoil.

While earthquakes, tsunamis, nuclear meltdowns, tornadoes, wildfires, flood and hurricanes roared from the natural world, a tidal wave of sovereign debt threatened to fracture the economic one, shaking the foundations of the 18-year-old European Union and its common currency and whipsawing U.S. equity markets in the process. Uprisings known collectively as the Arab Spring spread from Tunisia in January to rock Egypt, liberate Libya and threaten the Assad regime in Syria.

It was a bad year to be a dictator or terrorist. Hosni Mubarak of Egypt is on trial in the country he once ran, Libyan dictator Muammar Qaddafi was hunted down and killed by rebels and Osama bin Laden, mastermind of the 9/11 attacks, was shot to death by U.S. Navy Seals in a raid on his Pakistan compound. A missile fired by a U.S. drone in Yemen killed al-Qaeda operative Anwar al-Awlaki, a U.S.-born Muslim cleric accused of helping to plot attacks on Americans.

This month, the U.S. ended the war in Iraq after almost nine years, with the last combat troops rolling out on Dec. 18. That, and bin Laden's death, were among the "notable" positive developments in a year few will be sorry to see go, said Lee Clarke, a professor of sociology at Rutgers University in New Brunswick, New Jersey.

'Uncertainty Everywhere'

"What seems most compelling about so many of the events of 2011 is their uncanny similarity to the narrative that began to unspool in 1932, when the full shock of the Great Depression's impact began to be fully absorbed," said David M. Kennedy, the Pulitzer-prize winning historian and McLachlan Professor of History emeritus at Stanford University. "The implosion of over-stressed established regimes, the demonstrated obsolescence of vested ways of thinking, the emergence of new leaders, new ideas, new institutions, new ways of life -- the 'new normal' in realm after realm around the world."

It suggests that "the age of American global hegemony is almost certainly winding down," Kennedy said, and that 2011 "might mark the definitive end of the post-World War II and post-Cold War eras, and prove the portal to a future in which there are many more powerful and ambitious players on the world stage, more bitter political contestation at home, and more uncertainty everywhere than at any time since the 1930s."

'Scary Year'

Still, James E. Mueller, a historian at the University of North Texas Mayborn School of Journalism in Denton, said he thinks perspective is in order.

"My take on 2011, and most years, is that we've seen it all before," said Mueller, who is writing a book on the events leading to the 1876 Battle of the Little Bighorn, where George Custer and his 7th Calvary Regiment were routed by Indian tribes. The country was in deep recession, Native American uprisings threatened to uproot settlers from much of the West and former Confederate army units were fighting an insurgency throughout the South, with omens of rekindling the Civil War.

"That was a scary year," Mueller said. "Life is always tough, the news is always sensational, but we seem to always muddle through somehow."

The U.S. wasn't immune from protest in 2011, though it came in gentler form than it did for Egypt or Libya. In September, members of the Occupy Wall Street movement began camping in Lower Manhattan's Zuccotti Park. Organizers said they wanted to bring attention to U.S. income equality and what they consider to be the corrosive role of Wall Street in the economic crisis.

Nuclear Meltdown

The occupation ended on Nov. 15 when police moved in, took down tents and arrested about 200 protesters. The movement sparked similar protests in other cities around the globe.

Worldwide in 2011, natural disasters, led by the March 11 Japan earthquake and tsunami, took a $350 billion chunk out of the economy, according to reinsurer Swiss Re Ltd. Insurers were, in a way, lucky, with Swiss Re saying they are on the hook for only $108 billion of those losses.

The Japanese temblor and giant wave, which set off the Fukushima nuclear power-plant meltdown, amounted to the costliest of the calamities, with more than 15,000 dead and 3,400 missing, according to Japan's National Police Agency, and $35 billion in insured damages.

One month before, a magnitude-6.3 quake struck Christchurch, New Zealand's second-largest city, toppling buildings, trapping office workers and killing 181 people. Damage was estimated at $12 billion.

Torrential Rain

The U.S. took a beating from natural disasters as well, suffering $52 billion in damage through November, according to the federal National Climatic Data Center.

The biggest hit came from tornadoes roaming across the Ohio Valley and Southeastern U.S. in April that killed 321, pummeled metropolitan areas such as Tuscaloosa, Alabama, and Chattanooga, Tennessee, and resulted in $10.3 billion in losses. In August, Hurricane Irene dropped torrential rain across Connecticut, Vermont and other parts of the Northeast, resulting in flooding that caused at least 45 deaths and $7.3 billion damages, the center said in a report.

Then Virginia and much of the East Coast were shaken by a 5.8 magnitude earthquake that rattled the ground in more than 11 states, though it caused minimal damage. The tremor, whose epicenter was 84 miles southwest of Washington, was the largest to strike Virginia since 1897.

Debt Crises

While worldwide natural catastrophes garnered headlines, world leaders sought to avoid financial disasters. The European debt crisis, simmering since late 2009, escalated in April as Portugal joined Greece in seeking a bailout; Ireland followed in November. With hundreds of billions of dollars in sovereign debt and the stability of Spain and Italy in question, European leaders on Dec. 19 shored up their anti-crisis arsenal, channeling 150 billion euros ($196 billion) to the International Monetary Fund.

Prospects that the euro zone could fall apart have been at the heart of world stock market volatility. The costs would be "horrific," Paul Donovan, deputy head of global economics at UBS AG, told Bloomberg Television Dec. 16, risking "a global depression on the scale of the 1930s."

The U.S. had its own debt struggles. In August, Standard & Poor's lowered the country's long-term sovereign debt rating to AA+ from AAA, as Congress reached an 11th-hour accord to raise the $14.3 trillion debt ceiling. The change came, the ratings company said, because the debt deal wouldn't "stabilize the government's medium-term debt dynamics." The Obama administration called the move "political."

Fed Documents

So far, the downgrade seems to have hurt little but America's pride. Dollar-denominated financial assets have been appreciating since the Aug. 5 decision, according to data compiled by Bloomberg. Government bonds have returned 3.8 percent, the dollar has gained 7.2 percent relative to a basket of currencies and the S&P 500 Index of stocks has rallied 3.7 percent. Borrowing costs have fallen to record lows, with the average monthly yield in November on 10-year notes below 2 percent for the first time since 1950. The U.S. was seen as the best performing market in the world among international investors in a Bloomberg poll this month.

U.S. economic policy was in the news in March when the Supreme Court upheld a lower-court decision and ordered the Federal Reserve to release the details of emergency loans it made to banks in 2008. The records had been sought by Bloomberg News's parent company, Bloomberg LP, in a lawsuit after the Fed refused a federal Freedom of Information Act request.

Hacking Scandal

The data showed, among other things, that banks took tens of billions of dollars in emergency loans at the same time they were assuring investors their firms were healthy. On their neediest day, Dec. 5, 2008, the banks were in trouble so deep they required a combined $1.2 trillion, Bloomberg reported.

Across the Atlantic, another media company became a story. News Corp., controlled by Rupert Murdoch, closed its News of the World tabloid in July after revelations that staffers had been involved in hacking the mobile phone of a slain crime victim.

The scandal has led to at least 16 arrests, among them Andy Coulson, a former News of the World editor and one-time communications chief for Prime Minister David Cameron, and the resignation of several senior Murdoch lieutenants. On Dec. 20, the company's British publishing unit said it resolved seven civil lawsuits over the interception of celebrities' voice-mail messages to get scoops for the tabloid.

Throughout the year, the world was riveted by violent crimes, and sensational allegations.

Mass Shootings

In January, Representative Gabrielle Giffords, an Arizona Democrat, was shot in the head in Tucson while she met with constituents at a supermarket. The alleged gunman, 22-year-old Jared Lee Loughner, killed six people, including a federal judge, and wounded 12 others besides Gifford. Loughner potentially faces the death penalty.

In May, Dominique Strauss-Kahn, the French national heading the International Monetary Fund, quit after sexual assault allegations by a New York hotel worker landed him in jail under $5 million bond. Charges were dropped in August after prosecutors decided the accuser had repeatedly lied. The ex-IMF chief still faces a civil lawsuit over the matter.

Another mass shooting captured global attention in July. In Norway, 32-year-old Anders Behring Breivik set off a bomb in Oslo and later attacked a summer camp, murdering 77 civilians, many of them teenagers, some as young as 14.

London Riots

While Breivik had written extensively about what he called "cultural Marxism" and rising "Islamization" in his country, Norwegian forensic psychiatrists in November declared him insane at the time of the attack, saying he suffered from paranoid schizophrenia. He faces lifelong compulsory psychiatric treatment and likely will avoid a prison term, authorities said.

The next month, riots spread across London, Manchester and other cities and towns in the U.K., killing five, resulting in more than 3,300 arrests and causing an estimated $328 million in damage. British police, caught by surprise, were criticized for not stepping in more quickly or firmly in some cases. The uprisings' causes -- with some blaming racism and poverty, others a culture of entitlement -- are still being debated.

The riots cast a pall across Britain in what had been a year uplifted by the April 29 marriage of Prince William to Kate Middleton in Westminster Abbey. As many as 1 million people lined London's streets, and an estimated 2 billion watched on television. By some estimates, the wedding added about 620 million pounds ($971 million) to the country's tourism revenue.

Steve Jobs

In the U.S. one of America's leading public schools, Penn State University, was rocked in November when Jerry Sandusky, a former assistant to legendary football coach Joe Paterno, was accused of sexually assaulting or having inappropriate contact with at least eight underage boys on or near school property over a 15-year period. A grand jury returned a 40-count indictment against Sandusky, who has said he is innocent. The university fired Paterno and President Graham Spanier, saying neither had done enough after the allegations first surfaced.

The death in October of Apple Inc. co-founder Steve Jobs, who had pancreatic cancer, precipitated a global outpouring. Mourners flocked to Apple stores from New York to Hong Kong, while a crowd gathered in San Francisco's Mission Dolores Park for an iPhone-lit vigil.

Jobs wasn't simply a pivotal player in ushering in the age of personal computers, he was a digital visionary who changed the way music and movies are distributed and who, with the invention of the iPhone, took the concept of the cell phone to heights unimagined by competitors. He was 56.

Another death, of North Korean dictator Kim Jong Il on Dec. 17, elevated to the head of the nuclear state his son, Kim Jong Un, about whom little is known, including his exact age.

As the year drew to a close, President Barack Obama marked the end of the war in Iraq with a military ceremony at Joint Base Andrews outside Washington. An estimated 4,500 U.S. personnel were killed and about 32,000 were wounded in the conflict. The war cost the U.S. more than $800 billion.