Every Turkish schoolboy grows up learning about the multitudes of contributions Turkey has made to Western civilization. My favorite one, not in the textbooks strangely enough, is the croissant. The story goes that the croissant was first concocted by Viennese pastry chefs in celebration of the collapse of the Viennese siege by the Ottomans in 1683, with the crescent on the Ottoman flags serving as the inspiration for the design. Well maybe it is just a legend, but it sounds too good to reject outright ...
Here is a paper, by Murat Iyigun, with a much more important claim, namely that Europe owes its religious tolerance and ultimately the development of its secular institutions to the Ottomans. According to Iyigun, it is thanks to the military threat posed by the Ottomans that the Protestant Reform movement and its offshoots were able to grow and mature without getting crushed by the Catholic establishment. While arguments of this sort have been around, Iyigun is able to document a strong negative correlation between the incidence of Ottoman military campaigns in Europe and the occurrence of religious conflict within Europe. In Iyigun's words:
Utilizing a comprehensive data set on violent conflicts for a two-century interval between 1451 and 1650, I demonstrate that Ottoman military engagements in continental Europe lowered the number and extent of violent conflicts among and within the European states themselves. The Ottoman-threat-cum-European-cohabitation effects were long lasting and quantitatively very significant: in the 200-year span between 1451 and 1650, when there were roughly 1.5 new conflicts initiated among the Europeans per annum and about 5.1 conflicts per year in total (including those that had begun at earlier dates), Ottoman military expeditions in Europe lowered the number of newly initiated conflicts between the Europeans by about 35 percent, while it dampened longer-running confrontations on the order of about 20 percent. The intensity of military engagements between the Protestant Reformers and the Counter-Reformation
forces (such as the Schmalkaldic Wars, 1546-47, the Thirty-Years War, 1618-48, and the French Wars of Religion, 1562-98) did depend negatively and statistically significantly on Ottomans’ military activities in Europe too: during the interval of time between the birth of Protestantism in 1517 and the end of the Thirty-Years War in mid-17th century, Ottomans’ military expeditions in continental Europe depressed the number of a Protestant and Catholic violent engagement by about 25 to 40 percent.
These findings indicate that the European periphery influenced its economic and institutional history in a novel and hitherto neglected fashion.
Between this and the croissant, you would think the EU would be a bit more hospitable to Turkey's membership aspirations.