Remember Turkey is a Muslim country, albeit a "liberal" one with a significant Christian minority - as is Syria. On the face of it you might expect them to be mutually supportive.
But (leaving more distant history aside) Syria has long been a Soviet satellite, as Turkey has been coddled to be a Western one, and the current fight for access to and control of the region's resources (particularly water) has highlighted their differences more than their similarities.
In turn this questions the integrity of the powers behind them in terms of aid or resistance to the governing regimes and the rise of Isis - not to mention the various factions fighting to either overthrow or support them, or the Kurds and their nationalist aspirations.
It also raises serious doubts about the ultimate intent of nations like Saudi Arabia and Iran, both of which may be attempting to be seen as "good guys" but whose actions - overt or covert - could more easily be identified as bad.
The issues this raises for New Zealand - given National's sycophantic cosying up to the Saudis as their butchery under Sharia law threatens to out-do Isis for barbarism - are likewise turgid and complex.
All of which allows demagogues like Donald Trump, or "reluctant" warmongers like David Cameron, to vilify Muslims in general and Syrians (Muslim or not) in particular as terrorists-in-waiting if not fact and persona non grata in their countries.
In a cauldron of hate where one man's ally is another's mortal enemy, it has been said the only effective strategy - in attempting to manufacture an inclusive reformist government - is to back the sides one dislikes least.
The hate rhetoric of populists like Trump threatens to undermine even such modest intent, by turning the so-called moderates - those Syrian rebels who do not support jihad - into implacable foes.
Meanwhile about 30,000 foreign fighters are now part of Isis - unsurprising when you consider Chechnyan rebels were the original core - with Tunisians, Saudis, Russians, Turks and Jordanians, in that order, the major groupings, together with about 5000 from western Europe.
So to call Isis, or the influx of refugees into Europe, a purely Syrian problem is to overlook the complexities of the situation - and of the average Syrian's plight.
Just as to restrict or ban (or praise) people on the basis of their religion ignores whether they are, fundamentally, "good" or "bad" people.
Politicians prefer to voice issues in black and white, but the world comprises endless shades of grey. In that light, we are all Syrian.