What were the reasons for Cold War ? 

• Ideological Differences 

The USA had been governed by a democratic system since its independance . In a democratic society, two or more political parties can exist and the people have the right to choose the party of their choice . The party with the majoirty votes forms the government . Democratic socities largely follow the concept of capitalism where business and property were privately owned . USSR have a communist government where only a single political party exists - the communist party . In a communist state , there is no private ownership , everything belongs to the government and a classless society is formed whereby everyone is equal . 

Russia's communist government wanted to help other communist parties to overthrow their democratic government . Thus , the western European countries were worried that the communist would spread their ideas to their countries and incite similar revolutions there . The USA also viewed communist Russia as a threat to its political and economic security and influence . And when USSR faced the civil war , USA provided troops to help the anti communists,This led the communists to conclude that western capitalist countries aimed to destroy communism in Russia .After winning the civil war , the western countries did not recognised USSR initially till 1933

• Feelings of Mistrust 

Stalin signed the Nazi-soviet pact which made western powers distrust USSR , and the soviets remembered how USA sent troops to fight against the communists , this made the two countries to mistrust one another . When Stalin urged the Allies to open a second front to defeat Germany , there was a delay . The Allies wanted to wait until there was a chance of victory , but this caused Stalin to feel that the Allies wanted to minimise their own losses and hoped that Germany and USSR will destroy each other .The Americans had been also been secretly developing atomic bombs under the Manhattan Project , they did not tell USSR about it until its first successful test . Stalin believed that USA might use the atomic bombs on them and was suspicious of USA's intentions . This also lead to the arms race between USA and USSR as USSR sought to rapidly catch up with the USA's military powers and USSR became the second country to sucessfully make atomic bombs . 

• Differences in Goals 

Yalta Conference 

AIMS : 

Stalin was concerned about the future security of USSR , Churchill wanted to continue close ties with USA because he knew that Britain will not be an imperial power after the war . Roosevelt needed USSR's help in order to defeat Japan , hence gave into Stalin's demands . 

DISAGREEMENTS 

The western powers wanted Poland to be able to hold free elections and choose their own government , But USSR wanted Poland to be under their influence . Many invasions into USSR was through Poland and USSR wanted to safeguard its security . 

The western powers believed that a strong German economy is vital to Europe's recovery . However USSR wanted Germany to remain economically weak so it will not pose as a threat to USSR .

The western powers also wanted an economically vibrant and democratic Europe , but USSR wanted its own sphere of influence in Eastern Europe to safeguard its economy and security .

The Yalta Conference showed how the leaders have different objectives and it showed how their goals in Europe was very different . 

Potsdam Conference 

Churchill was succeeded by Attlee and Roosevelt was succeeded by Truman . 

Relations between USSR and the western powers worsened , Stalin had engineered a communist government in Poland and this was resented by the western powers . The USA was successful in inventing atomic bombs and hence did not need the help of USSR to defeat Japan anymore since they are militarily stronger . 

As compared to the Yalta conference , things did not go as smoothly during the potsdam conference , many important issues remained unsettled . There was no agreement of the amount of reparations Germany had to pay and there was no agreement of the type of government that will be established in Eastern Europe .

The Potsdam conference only brought out even more difference in ideologies and goals . 

• End of Wartime alliances

The removal of Germany meant that there was no need for USA and USSR to remain allies . WWII left Europe devasted and USSR and USA emeraged as the new superpowers , this agave USA and USSR the opportunity to increase their political and economic influence in Europe. Each sought to strengthened its own political and economic influence in Europe . American economic and security interests as well as the desire to support the political self determination of Europe clashed with the security interests and the ideological beliefs of the USSR . 

The USA was worried that USSR would try to spread their influence and establish communist governments in Europe , USSR on the other hand did not want USA to threaten its security and survial . This led to both nations competing for influence in Europe .

USSR also established satellites states around Soviet Union . Stalin saw this as a defensive measure to ensure USSR's security , however USA perceived this as USSR's act of pursuing an agressive plan to expand global communist influence . 

• Containment policies 

Containment was the American policy to prevent the spread of communism outside USSR while increasing its influence at the same time . 

THE TRUMAN DOCTRINE 

This policy aimed to provide economic and military aid to Greece and Turkey . Greece and Turkey depended on Britain for political and economic support before the WWII but however after WWII , Britain could no longer provide support as they were drained finacially . So in order to prevent the spread of communism , USA provided economic support to make Communism less attractive since weak states are more prone to be influenced by communist ideas .If more countries fall into communism , this would threaten America's interests .

THE MARSHALL PLAN 

This plan too provided economic aid to help countries rebuild their economy , this in turn would revive Europe's economy. However this policy is open to countries no matter whether they are under communist influence or not . After WWII , many European countries were drained fiancially , if they remained weak , they might be attracted to communist ideas and thus USA wanted to restrict communist influence by providing economic stability . In addition , this offer was also open to Soviet Union's satellites state . This was a targetted move to reduce Soviet union's influence in Europe .USA also needed strong trading parnters in order to maintain its own economy , therefore by helping other european countries to recover economically quickly , USA will be able to boost their own economy . The Marshall plan contributed to the revival of chemical , engineering and steel industries of participating countries . Hence , Marshall plan was successful at containing the spread of communism by helping countries to recover economically .