Sunday's suicide car bombing in Ankara has raised fears of an escalation in Turkey's long-running Kurdish conflict, as the country grapples with the Islamic State threat while relying on a security system weakened by a political crackdown, analysts say.

No-one has claimed responsibility for the blast which killed 35 people in the heart of the Turkish capital, but the government has pointed the finger at the outlawed Kurdistan Workers' Party (PKK), against which Ankara has waged a relentless assault since late last year.

Russian President Vladimir Putin said his forces have "on the whole" completed their task in Syria as he ordered the surprise withdrawal of the bulk of Moscow's forces.

But questions remain over why the Kremlin has chosen this moment to scale back its intervention in Syria and what the move could mean for the protracted conflict, now entering its sixth year.

Skeptics of North Korea's nuclear threat, and there are many, have long clung to two comforting thoughts.

While the North has the bomb, it doesn't have a warhead small enough to put on a long-range rocket. And it certainly doesn't have a re-entry vehicle to keep that warhead from burning up in the atmosphere before it could reach a target like, as it has suggested before, Manhattan.

A fierce, battle-hardened warlord with roots in Georgia and a thick red beard, Omar al-Shishani was one of the most notorious faces of the Islamic State jihadist group.

On Monday, the Pentagon confirmed that Shishani -- whose real name is Tarkhan Batirashvili -- died after being wounded in a U.S.-led coalition strike in northeastern Syria earlier this month.

The success of the anti-migrant AfD marks a turning point for Germany's usually stable and consensus-driven politics -- the rise of right-wing populists at the expense of old mainstream parties.

The accelerated splintering of the political landscape further erodes the moderate center, sparking disarray that will make coalition building more difficult, analysts warn.

But that hasn't stopped the billionaire real estate developer from making outrageous declarations on his foreign policy plans if elected president.

So far, the Republican frontrunner has said he would force Mexico to build a border wall to keep illegal immigrants out of the U.S. 

Rivals al-Qaida and the Islamic State group are cementing their presence in south Yemen in the absence of state authority and little opposition from pro-government Arab coalition forces, experts say.

For the first time since its campaign against Iran-backed Shiite rebels in Yemen began almost a year ago, warplanes from the Sunni Saudi-led coalition this weekend targeted jihadists in Aden.

The Syrian conflict has had outsized impact on global politics. Five ways the world has changed:

RISE OF ISLAMIC STATE

When hopeful pro-democracy activists in Syria took to the streets in 2011, they couldn't have imagined that five years later they might end up living as refugees in Europe.

Using smartphones to keep up with the news from camps and relatives' homes thousands of kilometers (miles) away, they mourn a revolt that gave way to an internationalized war.

A length of razor wire dangles onto a chain-link fence, clinking gently in the warm breeze. Long, thick grass smothers what once was a gravel prison yard. Animal droppings are everywhere.

Over the past 14 years, nature has won control of Guantanamo Bay's Camp X-Ray, the notorious holding center briefly home to nearly 300 detainees pulled from the battlefield after the US-led invasion of Afghanistan.