 More acute threat to the Polish – Lithuanian state came from Sweden. The balance of power in the north had shifted in Sweden's favor, as the Baltic neighbor was led by King Gustavus Adolphus, a highly able and aggressive military leader, who greatly improved the effectiveness of the Swedish armed forces, while also taking advantage of Protestant zealotry. The Commonwealth, exhausted by the wars with Russia and the Ottoman Empire and lacking allies, was poorly prepared to face this new challenge. Continuous diplomatic maneuvering by Sigismund III made the whole situation look to szlachta like another stage in the King's Swedish dynastic affairs; in reality the Swedish power resolved to take hold of the entire Polish-controlled Baltic coast, and thereby profit from the Commonwealth's maritime trade intermediary control, endangering its basis for independent existence.
