Why Russia is pulling its troops out

In March, Russian President Vladimir Putin announced, in a surprise move, that he was pulling the majority of Russian troops out of Syria. He said the aims of the six-month deployment had largely been achieved.
Syrian President Bashar al-Assad visits Russian President Vladimir Putin in October.
Syrian President Bashar al-Assad visits Russian President Vladimir Putin in October.
The Russian forces -- and particularly Russian air power -- played a decisive role in propping up Assad at a time when he appeared in jeopardy. Putin telephoned Assad himself to let him know about the withdrawal.
Assad's position appears more secure now than it did in September, when the Russian deployment began and officials said that the terrorist group ISIS and other Assad opponents were its targets.
But Russia may have paid a price for its involvement.
On October 31 -- in an incident that may or may not be related specifically to Syria -- a Russian passenger plane exploded over Egypt's Sinai peninsula, killing all 224 people aboard. Investigators believe a bomb was smuggled on board. ISIS claimed responsibility and posted what it claimed was a photo of the bomb.
And on November 24, Turkey shot down a Russian warplane that had been flying over Syria, claiming the plane had strayed into Turkish airspace and ignored warnings to change course. A pilot was killed.
Russia denied that the plane had violated Turkish airspace. But the US said it had verified Turkey's claim.