Which battle in 1620 in Moldavia forced the Commonwealth to sign a truce favorable to Sweden?
Polish–Swedish War (1621–25):  The Commonwealth, occupied by a serious war with Ottoman Empire (battles of Cecora and Chocim) was unable to send significant forces to stop Gustav Adolf, and was forced to sign a truce favorable to Sweden. Battle of Cecora (1620): The Battle of Cecora (also known as the "Battle of Ţuţora/Tsetsora Fields") was a battle between the Polish-Lithuanian Commonwealth (aided by rebel Moldavian troops) and Ottoman forces (backed by Nogais), fought from 17 September to 7 October 1620 in Moldavia, near the Prut River.
Battle of Cecora