However, few of the treaty provisions were ever fulfilled. The Tatar raids resumed in 1618 (or perhaps even 1617), as commanders of the Dobruja and Budjak Hordes left Iskender's camp during talks. At first, Żółkiewki could not divide forces and Tatars plundered unopposed, but he met the Iskender Pasha's force near Kamianets-Podilskyi (Kamieniec Podolski). On September 28, 1618, he drove it back while enduring heavy losses. In 1617 and 1619 Żółkiewski forced Cossacks to sign a new agreements ("umowa olszaniecka" and "biało-cerkiewna"). Boats were to be burnt and raids were forbidden. In exchange, the Cossack register was expanded, and the annual subsidy to Cossacks from the Crown was increased. However, Cossack raids did not cease, especially as they were encouraged by Muscovy. In July 1618, after many warnings to the Commonwealth, the young and ambitious sultan Osman II send a letter to king Sigismund III with the threats of a new war and the burning of Kraków. Since the Ottomans were involved in large-scale war with Persia, this was no more than a warning at the time. However, Osman planned for a war against the Commonwealth, in order to compensate for the heavy losses sustained against Persia, where, in the Ottoman-Persian wars of 1603–1611 and 1617–1618/1619, the Ottoman Empire lost the Caucasus.
In 1618, the Thirty Years' War began. Czech Protestants were supported by German and Hungarian ones. The Hungarians asked the then Prince of Transylvania, Gabriel Bethlen, for help and declared their wish to unite Hungary with Transylvania. Bethlen had been appointed to the office after the Sultan's removal of Gabriel Báthory (ordered to the troops of Iskender Pasha in 1613). He was anti-Polish and a loyal Ottoman vassal and had aspirations to extend his rule to Moravia, Bohemia, and Silesia. Polish hetman Stefan Żółkiewski warned Bethlen against joining the Protestant side and promised help against the Ottoman Empire; however, Bethlen answered that it was too late to change allegiances. When the fight was joined by Gabriel Bethlen on the Protestant side, his siege of Vienna threatened to extend Transylvanian rule (and thus Ottoman) to Bohemia and Silesia.