Before this question can be answered, it must be defined. First of all, there are always theoretical alternatives to any situation. So, I will limit the question to alternatives currently in existence at or around the end of the Second World War which could reasonably have been expected to rival the system being shaped by the U.S. Secondly, I will limit the question primarily to the economic aspects of the international system. Finally, we must determine when the period of “after the Second World War” came to an end. This must necessarily be somewhat arbitrary. I have chosen to limit the bulk of my research to the period of 1945-1953. The subsequent passage of time renders it difficult to disentangle the threads of the immediate post-war period from those that came afterwards. In addition, the broad outlines of the global system were more or less set  in place by this point, so it seems to be a convenient vantage point from which to survey the question at hand.
   It is my contention that there were several credible alternatives to the system being put forward by the U.S. By this I mean that each of these other systems had a real possibility of substituting for the U.S. Capitalist/Liberal Democratic version of international organization. These alternate systems are Communism, Democratic Socialism, and what I will refer to as Authoritarian Nationalism. I take Authoritarian Nationalism to be essentially the post-war successor to the ideas of fascism. In my opinion the international system that actually arose after the Second World War was a product of the interaction of all of the above mentioned systems, rather than the creation of a particular actor. In short, there were alternatives to an international system shaped largely by the position of strength of the United States, and in fact the international system was not shaped largely by the U.S.
   In the following sections I will outline the historical background to the period 1945-1953. I will outline the prevailing economic trends, and go on to look at the chances of each system for gaining a pre-eminent position in terms of global influence. In this section I will look particularly at the question of whether the U.S. had the ability to shape the international system to its own ends. Finally, I will conclude that the current pre-eminence of the United States in world affairs is a very recent phenomenon, and that the extension of U.S. global hegemony in the areas of cultural, military, economic, and political affairs backwards into the immediate post-WWII period is unwarranted. It is always easy to find indications that a process was inevitable after it has already come to pass. However, based on my research, I believe that the current triumph of American ideology was anything but inevitable after the Second World War.

II. History
A. “To 1945”
   The immediate post-WWII period was the result of a confluence of preceding currents in world affairs. The earliest of these currents was the rise of the United States as a world power. This was paralleled by the rise of Germany. At about the same time, the United Kingdom began its long decline from its position as the predominant power in the world system. Meanwhile, another current was running on an intersecting course. This was the series of events set in motion by the Russo-Japanese War of 1904. This war set the stage for the Japanese imperial expansion that would only be checked by American power 41 years later. It also laid the groundwork for the fall of Imperial Russia, and the rise of the Soviet Union.
  This period saw the rise of war time planning across much of the developed world, and the institution of central government planning as a permanent feature of the government of the USSR. This era also saw a decline in the free trade ideals that had been championed by the UK during its period of ascendancy. All of which led to a weakening of the faith in the free enterprise system. People began to see the enormous economic improvements that could be had from so-called “rationalization” of economic activity under the competent eye of government planners.
  The appeal of government control over the economy grew even more with the onset of the Great Depression. The failure of the free market system was plain to see on the streets of every city in the developed world. The experiences of the Great Depression led to a growth in economic nationalism, as well as a revival and expansion of government economic planning. The apparent successes in the USSR, Germany, and Japan under state-led planning also contributed powerfully to the idea that the Capitalist/Liberal Democratic model of international organization had outlived its usefulness. By the end of the Second World War, Germany and Japan had been defeated, but it was not at all obvious that this was as a result of problems with the politico-economic systems they had built. The USSR, following similar principles, had emerged from the war as a military superpower. Even in Germany, Japan, and Italy there had been enormous gains before the outbreak of the general world war. There was a case to be made for poor leadership rather than poor institutions.

B. “1945-1953”
   Politically, the period of 1945-53 saw a divergence between the U.S. and the USSR. At the same time, many other states were being pressured to fall into line with one champion or the other. However, this was a result of the weakness of these states, rather than a genuine desire to stand in the shadow of the two superpowers. In fact, these other states were already in the process of marking out independent agendas in all areas that did not deal directly with the U.S./ Soviet split. Yugoslavia in the Soviet sphere, and France in the U.S. sphere are early examples of this trend.
    Militarily this time was marked by early advances on the Communist side as they consolidated the occupation of Eastern Europe and North Korea. The Soviets were also engaged in supporting communist movements outside their sphere of influence. On the other hand, the U.S. was busy with demobilizing its forces and preparing to return to a normal, peacetime level of preparedness. Furthermore, America’s allies in Europe and Japan were already “involuntarily demobilized” as a result of the devastation of the recent war. The trend towards decreasing militarism in the American sphere was only reversed with the outbreak of the Korean War. But, even the Armistice showed only a determination to hold the line against Communist expansion.
   The whole span of time from the end of the Second World War to the end of the Korean War  was marked by dissension between the U.S. and it’s allies over the appropriate structure of the proposed Western system. But, the predominant world influence was that of aggressive Communist expansion. Major episodes in this expansion included the rise of the Iron Curtain, the Berlin Blockade, and of course the Korean War. The main U.S. response to this aggression was to try to shore up its allies, and to put into practice the recommendations of the so-called “containment policy.” This policy essentially called for a holding action against Communism until the inherent weaknesses of the system led to its collapse.

III. Analysis
   Finally, we come to the economic trends of the time. The U.S. was undeniably the single wealthiest, most economically secure nation on Earth. Many influential people argued that the American blend of laissez faire capitalism and democracy had been the main factor behind this happy situation. And if it worked for America, they argued, it ought to work for the rest of the world as well. This was the idea which underlay U.S. efforts to remake the international economic system. But the trend in the U.S. public (as distinct from elite) opinion was towards ever greater government intervention in the economic life of the nation. Americans were actually in favor of more government control in the area of food conservation that went to help the Europeans. Newspaper articles of the time are littered with appeals for America to turn off of the road to government planning, and assurances that the American economic system can “still be preserved.” Clearly, the U.S. establishment felt that it had to consolidate domestic public opinion behind the ideas of laissez faire capitalism and free enterprise. These internal problems hardly contribute to the image of the U.S. as dictating the form of the international system from a position of strength. The American elite could not even convince the population of the richest, most powerful country in the world that it should support the prevailing economic system. How much more difficult would it be to convince outsiders then?
   Quite difficult, as it turned out. In the Democratic Socialist heartland of Western Europe economic conditions were not good. It would not be unreasonable to characterize most Western European countries as wards of the U.S. during this period. A New York Times article entitled “Western Europe Nears Normality” written ten years after the outbreak of World War Two proudly reported the great progress being made. The average Frenchman was reported to be dressing “almost as well” as he did in 1939, and eating “almost as well.” Britain was looking up too. Only meat, fish, butter, cheese, canned fish, sugar, soap, and tea were still being rationed. Unfortunately, some other countries were not doing as well.
   In spite of their material destitution, the Europeans were determined to follow their own economic path. What they lacked in physical capabilities they made up for in the intellectual realm. Under the leadership of thinkers like Keynes, the Europeans marked out a very different conception of the ideal international economic system from the one being proposed by the U.S. They proposed to create a comprehensive social safety net, and protect their citizens from the shocks of world trade. Although the Western Europeans were nominally allied with the U.S. against the Soviet-led Communist system, they did not support the central tenet of the American system. Keynes himself wrote that capitalism “in itself is in many ways extremely objectionable”, and also that capitalism was “spiritually and morally bankrupt.”
  In contrast to the U.S., the USSR was in the position of having to try to convince its citizens and allies that central control and government planning were good things. But this was not as pressing a problem since the Soviet government was not bound by the same rules against violence and elimination of opposing opinions that existed in the Capitalist and Democratic Socialist camps. The Authoritarian Nationalists had the same advantages, and countries such as Spain and Taiwan were much freer to follow whatever economic policies seemed to be most appropriate in a given set of circumstances.
   So, given the state of the world in the immediate post-war period, what were the chances of any of these rival systems gaining a pre-dominant global influence?  I will look at each of the systems in turn and try to gauge its potential for gaining a world-wide following. Firstly, there is the Capitalist system. This system was strongest in the United States. America, being the wealthiest and most powerful nation in the international system could have used its power to dominate the global system. But there were several obstacles to U.S. pre-eminence. The most important of these was that no one really wanted a world dominated by U.S.-style capitalism. Even many people within the United States thought this was a bad idea. Throughout the Cold War, the U.S. elite was distracted by the need to keep domestic opposition to a minimum. This was accomplished through a combination of pro-free enterprise propaganda and persecution of dissenters from the official line. The most famous example of persecution was the House Un-American Activities Committee, but other methods of discrimination were used as well. Meanwhile, America’s allies were also stubbornly resistant to the demands of the Capitalist system. As was mentioned above, Capitalism was almost a discredited concept in Western Europe. Finally, there was the problem of U.S. isolationism. America was historically disinclined to take a leading role in world affairs, and this disinclination was only accentuated by the opposition of most foreign nations. Only a concerted propaganda effort in favor of U.S engagement in the global system was able to convince American’s of the need to take a leadership role in world affairs. So, the chances for the triumph of the U.S. position did not seem very good.
   Secondly, there is the Communist system. This system was strongest in the Soviet Union. While the USSR was economically less powerful than the U.S., it was still a superpower. More than that, the USSR was a superpower on the rise. Russia had gone from defeat at the hands of the Japanese in 1904 to rival for the title of world’s most powerful nation in only 41 years. Furthermore, the Soviets were ideologically committed to extending the reach of their economic system to the whole world. In terms of competition with other systems, the Communists were in an advantageous position. They were boosted by the prestige of being led by a world power that had risen from the ranks of  poor and weak countries. Like the Capitalists, they could claim that their system would make the world stronger and wealthier. But unlike the Capitalists, they added an explicit appeal to the brotherhood of man. The idea of “from each according to his capacity, to each according to his needs” was central to the ideology of the Communist economic system, if not to the actual practice. This had a tremendous appeal to disadvantaged people around the world. Finally, the Communist system had the advantage of missionary zeal. While the defenders of Capitalism were fighting what appeared to be a rearguard action against government encroachment, the Communists appeared to be the vigorous, progressive proponents of a system that would do away with the evils of the old Capitalist world. Finally, the much greater oppression within the Communist countries was less well-known than the oppression going on under the House Un-American Activities Committee, for example. Overall, the Communists appeared better placed to gain a position of pre-dominant world influence during the post-war period.
   Thirdly, there is Democratic Socialism. This system was strongest in Western Europe. Despite the fact that Western Europe was very weak at this time, it did have many of the world’s most persuasive thinkers and polemicists. It also exerted a disproportionate influence on world opinion through the medium of its extensive colonial networks and contacts with other influential world powers, such as the United States. The Democratic Socialist system had the attraction of claiming to work for the common benefit in a manner similar to that of the Communists. The system also claimed to protect people from economic shocks of different kinds. But in some ways it actually went the Communists one better. The system had some specifically economic similarities with the Communist system, but it could claim to avoid the worst excesses of Communism since it retained the civil rights and democratic procedures which the Communists had repudiated. Therefore, the Democratic Socialist system could take advantage of the popularity of the Communist economic ideas without bowing to the political demands of orthodox Communism.
   Finally, there is the system of Authoritarian Nationalism. This system was strongest in the former colonial countries, particularly in Latin America and Asia. It had no fixed set of economic dictates per se, but, like its fascist predecessors, it sought to raise up countries from the inside without any over-reliance on foreign powers. This was an attractive attribute in the colonies and former colonial areas, which made up the largest part of the Earth’s surface and population. These areas were naturally suspicious of powerful states such as the U.S. and USSR, and if anything were more suspicious of their former colonial masters. So any system that could claim to put these countries on an equal footing with their more powerful neighbors, without simultaneously binding them to those neighbors, was bound to have an appeal.
  Given these circumstances, the chances of eventual U.S.-led Capitalist domination seemed very slim indeed. Although the Communist system was economically weaker than the Capitalist system, this was no guarantee that it would fall of its own accord. Even with the containment policy in place, the system held on for almost another half century. People had been waiting for the Soviet Union to fall since 1917, and instead it had grown stronger and stronger. The Democratic Socialist system also seemed to be a strong challenger to the Capitalist system. It had a wider appeal, and many intelligent arguments to support its tenets. Even the Authoritarian Nationalist system could hope to rival the Capitalist system, if only because its potential adherents were so numerous. In short, the chances of U.S.-triumph were not good. And in fact, they would not be good for many years to come.
   Looking ahead from 1953 the system advocated by the U.S. would face many more challenges. The Communists would continue pushing at the boundaries of their system for almost 30 more years. The U.S. system was still to face the Cuban Missile Crisis, and the Vietnam War among other challenges. The U.S. also had to face down the challenges of its allies. The Democratic Socialist economies were destined to grow in strength to the point where they could challenge the Capitalist economies. Authoritarian Nationalism turned out to be much less of a threat. As it turned out, the “poor leadership” characteristic of the World War Two era Nationalist regimes was actually characteristic of the system in general, and this system gradually fell into disrepute as more and more promises went unfulfilled.

IV. Conclusions
 The U.S.-led Capitalist system was on the defensive in 1945. It was on the defensive in 1953. The Capitalist system was on the defensive against either Communist or Democratic Socialist challenges all the way up to the 1980’s. The triumph of the U.S. and U.S. economic ideals in the 1990’s and 2000’s, are a product of the collapse of any plausible alternate systems. With the loss of the Soviet Union as a champion of Communist economic goals, and the abandonment of costly social entitlements in the Democratic Socialist sphere, the system favored by the United States has triumphed by default. This outcome was not inevitable. There was a good chance that the U.S. itself would have gone down the road to state planning and central control. Many American’s actually favored this path over the one that was chosen. And, without American backing, the Capitalist system might have faded into history. There was also the possibility that the Communist and Democratic Socialist systems could have joined forces to “contain” the U.S. There were strong Communist movements within Western Europe, and the two economic systems were at least partly compatible.
   So, the U.S. was constrained from exerting an overwhelming influence on the international economic system because there were several potential rivals to its leadership. The U.S. was also constrained by domestic ambivalence towards the ideals espoused by the elite. It has only triumphed with the end of the Cold War and the collapse of its major rivals. The statement: “After the Cold War, there was no alternative to an international system shaped largely by the position of strength of the United States” is probably correct. But in the case of the Second War it is undoubtedly not correct.

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