BRUSSELS - Turkish President Tayyip Erdogan makes a long-awaited trip to Brussels on Sunday, officially a two-day state visit to Belgium, that will be dominated by EU meetings over Europe's migration crisis and the fight against Islamic State militants in Syria.
Moscow's commencement of bombing raids in Syria could bring Russian warplanes to the very borders of the NATO country, now itself being used as a base for US and allied air strikes. The dangers of unintended clashes, and uncertainty over Russia's intentions, have raised concerns in Western capitals.
Tensions over Turkey's stalled EU bid, a Turkish government corruption scandal and a canceled visit by Erdogan as prime minister in 2011 meant the red carpet welcome has been put off again and again for the leader who the West worries is becoming increasingly authoritarian after 13 years in power.
The EU has been especially critical of a crackdown on media in Turkey, which languishes far down global press freedom rankings. Scores of people have been investigated on accusations of insulting Erdogan, who remains nonetheless Turkey's most popular politician.
Outside the EU it may be, but Turkey has a key role on its eastern borders.
Europe's worst migration crisis since the break-up of former Yugoslavia now has EU governments looking to Erdogan to help stem the flows of refugees as record numbers of people flee Syria's civil war and the rise of radical militants in Iraq.
"It couldn't come at a better, or a worse time," said one senior EU diplomat involved in Europe's Turkish policy.