What two countries participated in the war between 1617-1618 in order to take Polish pressure off of Russia?
Polish–Swedish War (1617–18): The Polish–Swedish War (1617–18) was a phase of the longer Polish–Swedish War of 1600 to 1629. Polish–Swedish War (1617–18):  It continued the war of 1600–11 and was an attempt by Sweden to take Polish pressure off Russia. Polish–Swedish wars: The Polish–Swedish Wars were a series of wars between the Polish–Lithuanian Commonwealth and Sweden.
Polish–Lithuanian Commonwealth and Sweden