A man shovels snow from the roof of the soccer arena in Munich, Germany on Jan. 28. Christof Stache/AP
Tennessee State Trooper, Lt. Preston Donaldson (r.) helps jump start Tenn. State Trooper Gil Smith's car at the State Capitol building after it would not start due to the cold weather on Jan. 29, in Nashville. A winter storm brought several inches of snow to Tennessee. Josh Anderson/AP
Vendors carry their wares during the start of a day's work on a foggy morning in Allahabad, India, on Jan. 29. North India has experienced severe fog this month, with over 1,200 domestic and international flights disrupted and 200 others cancelled at the Indira Gandhi International Airport in New Delhi alone, according to a news agency. Rajesh Kumar Sing/AP
A woman struggles with her umbrella while crossing 42nd Street on Jan. 25, in New York. A storm from the southwest brought rain and high winds to the Manhattan area. Don Emmert/AFP/Newscom
A girl looks out from a frozen bus window on Jan. 25 in the western Ukrainian city of Lviv, where temperatures reached below zero. Yuriy Dyachyshyn/AFP/Newscom
The frozen river Oder is seen from a bridge in Frankfurt/Oder on Jan. 27, as the border river between Germany and Poland is covered with ice. After the coldest night of the year, meteorologists announce milder temperatures in the next days. Michael Urban/AFP/DDP/Newscom
A pet plays on a snow sculptures in a snow-covered park in Minsk, Belarus, on Jan. 29. Sergei Grit/AP
A statue is covered with snow at a park in Berlin, Germany on Jan. 28. A storm front covered much of Germany with snow Wednesday night into Thursday, adding to what has been an unusually cold and snowy winter. Ban Wei/PTS/Newscom
Foreign tourists take cover as a helicopter takes off, while waiting their turn to be evacuated from the Machu Picchu Pueblo archeological site in Cuzco, Peru on Jan. 29. Peruvian authorities are hoping to evacuate the last tourists stranded after heavy rains and mudslides in Peru blocked the train route to Machu Picchu, but the Inca citadel is likely to stay closed for weeks even if the weather improves. Martin Mejia/AP
A multi-vehicle pileup is seen in the southbound lane of Highway 65, one mile south of Mason City, Iowa, on Jan. 25. The National Weather Service said snowfall ranged from 1 to 4 inches, but winds were blowing up to 35 mph, with gusts near 45 mph. Bryon Houlgrave/The Globe Gazette/AP
A Dutch amateur skiier on the Weissensee in Austria has a frozen moustache, on Jan. 29. Vincent Jannink/AFP/Newscom
Sophisticated and lethal, growing in number, Islamic State and other extremist groups won't become a global force. Here's why.
BySeth G. Jones, Contributor
Raqqa Media Center of the Islamic State Group/AP
Mullah Abdul Rauf Khadim looked like any ubiquitous insurgent commander in southern Afghanistan. He had a sunbaked complexion, serried black beard, charcoal eyes, and the usual accessory – an AK-47 slung over his shoulder.