The Polish-Swedish War (1617-18) showed that the Swedish Army, despite several reforms, was still unable to defeat the Polish-Lithuanian Commonwealth, despite the fact that Poland - Lithuania at the time, was involved in other conflicts, and had sent inadequate forces to Livonia [REF].
Gustav Adolf was well aware of the ongoing conflict between the Commonwealth and the Ottoman Empire (see Polish-Ottoman War (1620-21)), and decided to take advantage of it [REF].