Photo Gallery Turkey and Russia Ratchet Up Tensions

A photo from the Russian Defense Ministry website showing Russian bombers dropping their payloads on targets in Syria. Moscow's intervention in the Syrian war has increased tensions with Turkey, but has also served to drive a wedge into the NATO alliance.

German Chancellor Angela Merkel is heavily reliant on Turkey in the refugee crisis, but she is wary of offering Russian President Recep Tayyip Erdogan any concessions that might encourage him to intensify his ongoing confrontation with Russia.

Putin's intervention in Syria at the end of September has dramatically expanded the implications of the Syrian civil war. But it has also given him leverage against NATO and, more recently, against Turkey.

The Turkish-Russian animosity began in earnest in November when the Turks shot down a Russian warplane after it violated Turkish air space. "We have to avoid that situations, incidents, accidents spiral out of control," warned NATO General Secretary Jens Stoltenberg in the wake of the incident.

Merkel has been sharply critical of Putin's actions in the Crimea and eastern Ukraine, but she is opposed to breaking off all contact with the Russian president. She is concerned about being dragged into a conflict against Russia by Turkey.

Turkish President Recep Tayyip Erdogan has been lobbing artillery at Syrian Kurds across the border. But after Turks shot down the Russian warplane in November, Putin began supporting the Kurds.

Recently, global attention has focused on the brutality with which Russia has been pursuing its aims in Syria. This image shows a hospital that was destroyed, allegedly by Russian bombs, in the Idlib province of Syria on Feb. 15.