Hyvää huomenta. Tervetuloa Nato Finlandiin
This map shows the significance of Finland joining NATO. The border between Finland and Karelia is mostly wilderness and complete wilderness in Murmansk Oblast. The one major road between St. Petersburg and Murmansk is the Achilles heal of Russia’s northern fleet. Finland’s military is one of Europe’s best. Russia ain’t happy today. They are cornered, which makes them dangerous.
Sorry about the map. There’s not much out there. Check Google maps for more detail.
“Murmansk is the Achilles heal of Russia’s northern fleet.”
Russia probably has nuclear-armed submarines off the east coast of the USA.
A lot of those areas between the current Finnish border and the red line are or were ethnically Finnish. The Soviets took about 10% of pre-World War II Finland, and Russified the territory, with many Finnish residents of the conquered area going to Finland. Nonetheless, many of the residents, though not Finnish, speak languages similar to Finnish.
During World War II, the Germans and their Finnish allies were unable to sever the link between Murmansk, the USSR's main White Sea port, and the rest of the country. That port was a principal entry point for American and British aid during World War II.