What historical events contributed to the soviet union's desire to control the nations on the western border?

Russia suffered outnumbered invasions over its western border throughout history. These invasions include Napoleon in 1812, Nazi Germany -WWII, Germany and the Austro-Hungarian Empire during the WWI, England in 1854, Poland in 1609, and more. 

Each of these invasions was destroying and ravaging. Russia always lost more soldiers than the raiding armies did. Retreating slowly from the enemy was the battle’s strategy.

After the second world war, about 25 million soldiers died. The Soviets then wanted to stop more invasions,thus, kept territories along their western border they have invaded and conquered. They consider it as the “buffer zone” between them and the west.

by 1890, the united states had by far the world's most productive economy. american industry produced twice as much as its closest competitor--britain. but the united states was not a great military or diplomatic power. its army numbered less than 30,000 troops, and its navy had only about 10,000 seamen. britain's army was five times the size of its american counterpart, and its navy was ten times bigger. the united states' military was small because the country was situated between two large oceans and was surrounded by weak or friendly nations. it faced no serious military threats and had little interest in asserting military power overseas.

operation overlord was the codename for the battle of normandy, the allied operation that launched the successful invasion of german-occupied western europe during world war ii. the operation was launched on 6 june 1944 with the normandy landings