Turkey has long been accused of tolerating and even collaborating with Islamic State (IS) jihadists but in recent months it has shown signs of sharply toughening its line against the group.

Now, after the suicide attack in Istanbul on Tuesday that killed 10 German tourists and was carried out by an IS bomber from Syria, will Ankara launch an all-out assault against the group to push it out of Turkey and end its presence on the Syrian border?

The 2011 revolution that toppled Tunisia's regime has awoken extremism in the country after decades of repression, turning it into a target for attacks and a key exporter of jihadists.

Analysts say the current state of affairs is a result of the legacy of ousted president Zine El Abidine Ben Ali's 23 years of iron-fisted rule, as well as Tunisia's porous borders.

The world will heave a collective sigh of relief when west Africa's Ebola epidemic is finally declared at an end after claiming more than 11,000 lives over two years.

But with a cure still out of reach, and no vaccine on the market, are we better prepared for next time?

On January 14, 2011, Tunisians packed the streets of their capital and shocked the world by overthrowing longtime dictator Zine El Abidine Ben Ali.

The revolution shook the Middle East, setting off the hopeful uprisings that came to be known as the Arab Spring.

Dreams rarely come true, at least not for long.

For a few incredible months, the prospect of a better life in Europe seemed within grasp, attracting a wave of more than 1 million migrants from the war-torn, poverty-stricken Middle East and Africa. To get there, they risked their lives at sea and parted with fortunes.

Long one of Iran's few Sunni Arab partners, Sudan has cut ties with Tehran in the latest step in its move towards Saudi Arabia as Khartoum seeks to end its isolation and right its economy.

The impoverished east African state followed Riyadh in severing relations with Iran, saying it was responding to attacks on Saudi diplomatic missions in Iran after the execution of a Saudi Shiite cleric.

German Chancellor Angela Merkel has been forced to change tack on her liberal stance towards refugees, after a spate of assaults during New Year's Eve celebrations blamed on asylum seekers.

Turning away from her mantra of "we will manage this" over the record influx of asylum seekers that reached 1.1 million last year, Merkel has now backed changes to the law to ease the process of expulsion for those convicted of crimes.

When asylum seeker Asim Vllaznim heard about the New Year's Eve spate of sexual attacks in Germany, blamed on a crowd of migrants, he says his heart fell.

"Our first reaction was: now the Germans will hate us," said the 32-year-old Kosovar, sitting with his family in their room at a migrant shelter in the western city of Cologne.

The arson attack on Saudi Arabia's embassy in Tehran that prompted Riyadh to cut diplomatic ties with Iran was initially seen as a victory for hardline opponents of President Hassan Rouhani.

But analysts say the incident could ultimately backfire on his foes ahead of Iranian parliamentary elections next month, giving the moderate Rouhani ammunition as he confronts conservatives and works to restore his country's international reputation.

Western nations agree military action must be taken soon to combat the growing threat of the Islamic State (IS) group in conflict-wracked Libya, but analysts say there are no easy options.

Air strikes by an international coalition helped rebel forces to overthrow Libyan dictator Moammar Gadhafi in 2011, but they have not been enough to dislodge IS from Syria and Iraq.