Turkey’s relationship with Russia seems to keep both sides on edge. Today, President Recep Tayyip Erdogan is praising Russia as Turkey’s partner in a new Syrian operation. He is proclaiming that Ankara will proceed with its purchase of the S-400 weapons system from Moscow — something he said was in doubt earlier in the week.

Last week, as Erdogan was visiting Ukraine, he directed a pair of irksome announcements toward Russia, one regarding the Crimean Peninsula and one about new import restrictions on Russian agricultural goods.

Erdogan traveled to Ukraine Oct. 9 for the countries’ High-Level Strategic Council meeting. He also met with Ukrainian President Petro Poroshenko. The sides signed a number of agreements and said they would work to raise the volume of bilateral trade to $10 billion a year, from $3.8 billion currently. Also, Turkey’s leading defense company, ASELSAN A.S., signed a $43.6 million contract to supply a communications system for the Ukrainian armed forces in 2018.

Poroshenko said he was satisfied with the negotiations’ results. “The meeting … has been completed in a very trust-based and constructive atmosphere,” he said during a joint briefing with his Turkish counterpart.