Top news of 2014 left public wanting answers

More than nine months after searchers began scouring the seas for a Malaysia Airlines jetliner that vanished with 239 people aboard, the catastrophe defies resolution.

The long hunt for clues to Flight 370's fate set the tone for many of the headlines that defined 2014. It was a year that often left the public and its leaders grasping for answers.

From Ukraine to the Middle East, from the Ebola threat to the tensions exposed by police killings in Ferguson, Missouri, and elsewhere, many stories fed into a growing sense of frustration.

The conflict over Ukraine stretches back to President Victor Yanukovych's ouster in February. When Russia grabbed the Crimean peninsula, it set off a standoff reminiscent of the Cold War.

Many of the biggest news events capture the public's attention for just a few days, or perhaps weeks, before slipping from view. Not in 2014.

The Ebola crisis began with a case in Guinea last December. A year later, the disease has already killed at least 6,000 people. Nearly all of those deaths came in three west African countries. As the year neared an end, the World Health Organization questioned reports of progress in containing the disease based on data it says is filled with inconsistencies.

Meanwhile, violence in the Middle East again took command of the headlines.

In Gaza, a 50-day war killed more than 2,100 Palestinians and 72 Israelis. But it ended with no hint of a route toward resolution.

After nearly four years of civil war in Syria, ISIS' rapid expansion and videotaped beheadings of Western hostages inspired a U.S.-led campaign of more 1,000 bombing attacks on ISIS strongholds in Iraq and Syria. As the year ends, leaders have warned that their vows to destroy the insurgency could take years to fulfill.

"We recognize that hard work remains to be done," U.S. Secretary of State John Kerry said.

Americans turned their attention to suburban St. Louis, where in August a white police officer fatally shot black 18-year-old Michael Brown. Exactly what happened was clouded by conflicting witness accounts. Brown's death, and a grand jury's decision not to charge the officer, prompted widespread anger over law enforcement's treatment of young, black men.

The larger narrative of 2014 is of a world faced by daunting challenges and few answers within reach. That was clear in October, when Peter Foley, an Australian coordinating the hunt for the vanished Malaysia Airlines jet, faced questions about its direction.

"We are in for the long haul," Foley said.