Turkey's downing of a Russian war plane on the Syrian border risks inflicting significant damage on relations between Moscow and Ankara, even if they both have an interest in avoiding a permanent rupture.

Modern Turkey and Russia are the successor states of empires that fought over three centuries of war from the late 16th century for the Black Sea and Caucasus but in recent years forged a sometimes uneasy but pragmatic alliance.

President Vladimir Putin has found himself in a bind after the downing of a Russian warplane by Turkey, which highlights the risks of his gung-ho Syria campaign and the difficulty of forging consensus on the war-torn country's future.

The dramatic escalation in tensions between Russia and NATO member Turkey comes as Putin prepares for talks Thursday in Moscow with France's Francois Hollande on building a broad coalition to fight Islamic State (IS) jihadists.

When Boko Haram captured territory in Nigeria's northeast last year and declared a caliphate, there were real fears for the sovereignty of Africa's most populous nation.

A deadline is looming for the military to end the six years of violence, with signs that troops have wrested back control of most of the towns and villages lost to the Islamists.

France has been one of the strongest voices pushing for the removal of Syrian President Bashar Assad, but the past four years have seen its strategy fail and its diplomatic weakness exposed.

"At its heart, it's a story of missed opportunities," said a government source, speaking on condition of anonymity.

Several Eastern European countries are becoming increasingly worried that the West may abandon Ukraine in return for Russian backing in Syria, as Paris, Moscow and Washington develop closer ties in the fight against the Islamic State jihadist group.

The three Baltic states, which were under Moscow's thumb until 1991, were particularly spooked by Russia's annexation of Crimea from Ukraine last year and are concerned about the Kremlin's territorial ambitions.

A fireman of Algerian origin, Faisal helped evacuate thousands from the Stade de France during the Paris attacks, guiding panicked football fans to safety as suicide bombers blew themselves up outside.

Now he fears the November 13 massacre across the French capital will deepen a dangerous "them and us" schism between France's five-million-strong Muslim population and the rest of society.

On the outskirts of the Syrian Christian town of Sadad, children play in front of a cannon fired just hours ago in an ongoing battle against the Islamic State group.

Soldiers and pro-regime militiamen nearby look on with amusement at the children, who appear oblivious to the fact that their ancient town is now in the sights of the jihadist group.

United by the trauma of terrorism, 14 years apart, New York and Paris have exhibited the same fortitude and determination to overcome the tears and fears with love, life and laughter.

Experts say this is the best possible response to such horrors.

The family homes of the suspected mastermind of the Paris attacks and one of the suicide bombers stand only a few blocks apart in the Belgian capital's Molenbeek neighborhood. After a string of attacks in recent years linked to its grimy streets in central Brussels, a key question arises: Why Belgium?

The tiny nation renowned for beer, chocolates and the comic book hero Tintin is now suddenly infamous for Islamic extremism — and the easy availability of illegal weapons.

More armed police are to be deployed in London after the Paris attacks, but the move is unlikely to herald a shift toward providing weapons to most officers in the largely unarmed British force, experts said.

Britain is proud of being one of few countries where police usually do not carry guns, and the sight of heavily armed counter-terrorism police officers in recent days is highly unusual one for many people.