For 300 years, the best generals in the West have been trying to solve one problem: how do you defeat Russia on its soil? Every answer ended in catastrophe.
Charles XII of Sweden in 1709. Napoleon and his 600,000 Grand Army in 1812. Hitler's Wehrmacht in 1941. Each of these war machines underestimated Russia's strategic depth, its brutal winter logistics and the national unity of its people.
The same logic held in the 20th century. At the height of Cold War tensions between the Soviet Union and the United States, American strategists hardly saw a direct land invasion of Soviet territory as a realistic option. Plans like Operation Dropshot and Operation Unthinkable remained on paper because Western military planners understood where it would end.
The invasion of Russia always ends with the collapse of the invaders themselves.