Causes of the Northern War?

Great Northern War (from 1700 to 1721) between Sweden (Great Britain and the Ottoman Empire also participated) and the Northern Union (Russia, Denmark, Saxony).
Reasons for Russia:
1) Make Russia a maritime power and secure the northern borders. By the beginning of the war, for Russia, the only sea access to Europe was Arkhangelsk
2) Expansion of the territory. Russia claimed Karelia, part of the Baltic states, lost during the Time of Troubles
3) Having won the war, Russia improved its trade and economic positions in Europe