Europe was the main scene of war but also the culprit for the two World Wars. Therefore, after the Second World War, the states that won the war, but especially the USA together with the USSR, sought to ensure that there were no more reasons for war in Europe, but also no ideologies that would propagate the war. Therefore, the powers thought to divide nazi Germany, erase as much as possible the adherents of the nazi and fascist currents, and to reconcile the European countries.

The reasons for conflict on the European continent
History shows that there are several reasons why France and Germany, Italy, and the Netherlands have been in conflict for a long time. Among these reasons we can highlight: 1) the desire to control the Ruhr basin, which holds the largest coal resources in Western Europe; 2) competition for the domination of Europe, etc.
The European Union idea
After the Second World War, the European states were ravaged by crises, so they needed a way to recover. While the USSR was busily occupying and managing Eastern Europe, the Prime Minister of Great Britain, Winston Churchill, came to Europe with the idea of forming the United States of Europe, invoking that only a united and peaceful Europe is a Europe of prosperity and one capable of development.
Europe went closer to the idea of a United Europe in 1947 when the US president H. Truman signed the Marshall Plan. This Plan came in front of the European states with economic aid with the purpose of recovering Europe after the War. This plan proposed to rebuild Europe after the War, but it also addressed some conditions to the European states in exchange for financial aid, namely the obligation to cooperate in order to benefit from this financial aid.

The Marshall Plan, Western Europe, and the USA
The United States were interested in rebuilding Europe to grow its own economy. Europe has always been a strategic partner for the USA. It was and still is, a large market for American products, but also a large producer for the American people. But once time passed, the USA considered the possibility of the USSR expanding all over Europe, something that would have clearly isolated America. So, the USA decided to give financial aid to Europe to restore it economically. But no help comes for free. So, this help from the USA translated into political control of Western Europe. And to ensure that the European states respect their part of the deal and that the money is not spent on other domains than the mentioned ones the aid from the Marshall Plan came to Europe in the form of food, grants for equipment, investments, etc.
Initially, this plan was not approved by Moscow leadership. Thus, the plan was accepted only by the countries that came under the influence of the United States after the new world order, namely 16 states: Austria, Belgium, Denmark (with the Faroe Islands and Greenland), France, Greece, Iceland, Ireland, Italy (and San Marino), Luxembourg, the Netherlands, Norway, Portugal (with Madeira and the Azores), Sweden, Switzerland (with Liechtenstein), Turkey and the United Kingdom.
One of the reasons that made the European countries cooperate was one of the Marshal’s Plan specifications, namely, it insisted that European countries manage the finances by themselves. As a result, a Committee for European Economic Cooperation was immediately formed, and in 1948 were laid the foundations of the Organization for European Economic Cooperation (OCEE).
In 1952, the organization went into decline starting from the sudden stop of the Marshall Plan and the directing of attention to NATO. In 1961, OCEE was replaced by OECD, turning into an international body, with today 38 member states from all over the world.
NATO
Meanwhile, in 1949, the North Atlantic Treaty was signed in Washington. Although many of the official speeches claimed that NATO was formed only to withstand the USSR and prevent the communist expansion in Europe, the formation of NATO was possible only after the USA and its allies communicated with the USSR and explained the real reason for building the military alliance, which was about preventing nationalist militarism in Europe, encouraging political integration in Europe, while preventing the communist expansion remained a hidden goal.
At that time, Europe was dominated by a nationalist mindset, the reason why we find in most books published at that time a cold attitude towards foreigners, other ethnicities, and nations, a tendency of some nations to dominate others, to consider themselves supreme, etc. This attitude seemed quite normal in Europe if it is for us to look into history. Europe had always been a continent of wars, France, Spain, Germany, Austria, Hungary, Greece, Turkey, Great Britain, and Russia, were throughout history great powers interested in dominating the continent. Therefore, eradicating this rooted nationalist thinking was quite difficult and required a special measure such as a military alliance – the case of Germany after WWI proves it very well.
So, the Alliance served its purpose very well, which satisfied both the European states that were able to preserve their political, economic, and social regime, but also the USA that kept Europe as its sphere of influence, which later was expanded.
P.s. USA came into the IIWW on December 7th, 1941 when the Japanese attacked Pearl Harbor, while Europe had already 2 hard years of war and was begging for help.
From here we can see the real American interest in Europe, which was not about protecting and really preventing it from poverty but about letting the European powers be weakened by the war and intervene only to be on the side of the winners to change the world order, and be a leading power.

Moscow’s Plan for the Economic Recovery of Eastern Europe (CMEA)
In response to Marshall Plan, in 1949 USSR created a program of economic cooperation between the countries of the Soviet bloc, namely the Council for Mutual Economic Assistance (CMEA or Comecon). This type of cooperation was very different from the western European one. In western Europe we can find the USA model of economic and political cooperation while in eastern Europe followed the USSR model, which was based only on bilateral trade relations and trade credits between the members. The fact that it did not involve stronger cooperation between the members prevented them from achieving a better result while the countries remained focused on their internal policies instead of designing a common response to overcome poverty and the crises after the war.
USSR’s response to the Marshall Plan shows us easily the beginnings of the Cold War translated into a competition between the USA and the USSR in the economic, military domains, and political influence in Europe.
Conclusions
The Marshall Plan represented an experiment for the Europeans, which showed them in the end that cooperation brings more prosperity than individual national actions. This convinced the European states that Europe is a strong international actor only when the European states cooperate and act as a whole and not divided.
Only after the experience gained following the cooperation during the Marshall Plan, Europe thought about laying the foundations of European Communities based on communication and cooperation for economic and social development.
Sources:
Comisia Eurpeana, 2021. Winston Churchill: calling for a United States of Europe. Accessible at: european-union.europa.eu/system/files/2021-06/eu-pioneers-winston-churchill_en.pdf
Uniunea Europeana, 2023. Istoria Uniunii Europene. Accesibile at: european-union.europa.eu/principles-countries-history/history-eu/1945-59_en
CVCE, 2021. The Marshall Plan and the establishment of the OEEC. Accessible at: cvce.eu/content/publication/1997/10/13/7cbc25dd-0c8d-49b1-924c-53edb2a59248/publishable_en.pdf
OECD, 2023. Organisation for European Economic Co-operation. Accessible at: oecd.org/general/organisationforeuropeaneconomicco-operation.htm
NATO, 2022. A short history of NATO. Accesibile at: nato.int/cps/en/natohq/declassified_139339.htm