The events of Second World War played a crucial role in the rise of the United States and in shaping its post-war foreign policy. It was this war, which determined the exact nature of power and influence that future superpowers needed to possess in order to dominate the rest of the world. Oddly enough, 'might' as we understood previously was replaced by diplomatic influence, which was to be amassed more through economic means than military methods.
The principle of 'Might is Right' was what governed the world till the end of 19th century. However this principle was modified somewhat in early 20th century by the two Great Wars, which are responsible for changing the face and definition of power. The fact that now powerful countries dominate the rest of the world through 'majority is authority' principle is the direct result of World War II events. Nowhere does this principle seem to be as influential as in the United States. After the second Great War, it was clear that the more people you controlled through economic or diplomatic means, the better were your chances to become the ultimate winner. This is how power or might yielded to majority.
It is extremely important to understand this principal thesis before we begin our discussion on the subject of effects and consequences of World War II on the United States. The reason United States and its allies made former world powers suffer an excruciating defeat in WWII was not because of sophisticated weapons or advanced atomic technology. It was more because of the support that Allies had managed to amass prior to the Normandy attack. They knew that more important than weaponry was numerical strength and global influence, a principle that the United States later incorporated in its business activities and foreign policy to become the single most powerful nation of the world.
Kenneth N. Waltz "For more than three hundred years, the drama of modern history has turned on the rise and fall of great powers. In the multi-polar era, twelve great powers appeared on the scene at one time or another. At the beginning of World War II, seven remained; at its conclusion, two. Always before, as some states sank, others rose to take their places. World War II broke the pattern; for the first time in a world of sovereign states, bi-polarity prevailed." 
In this paper, I have focused on the effects and consequences of World War II on the United States to prove that while World War was not exactly a 'good war', it had a profound positive impact on economic conditions and International relations of our country. While we would hate to admit this, but it was actually this war, which has played a dominant role in giving United States the prominence and significance that, it now enjoys on the International political scene.
In the First World War I, human race witnessed the death of individual rights and civil liberty. Inflation soared, poverty increased, businesses suffered and these compound economic problems led to the Great Depression of 1929. This war had been so profound in its negative impact on every sphere of life that a second war of the same magnitude was unthinkable. With the world economy slowing down, inflation rising, human rights shrinking, people were certain that the world wouldn't think of indulging in a similar war ever again. But this proved to be nothing more than wishful thinking when the world entered another bloody war, which was by all means more devastating than the First World War.
United States' current foreign policy and the nature of its relations with the International community were largely shaped by the events of the Second World War. This was the time when United States made the 'might' yield to 'majority' and since then has been seeking to expand its influence in various different ways. Events of WWII and its consequences are responsible for laying the foundation of today's most hotly debated issue i.e. Americanization.
The real purpose of United States' participation in this war was described as maintenance of peace and protection of human rights.."Rapid and united effort by all of the peoples of the world who are determined to remain free will insure a world victory of the forces of justice and of righteousness over the forces of savagery and of barbarism." But this purpose appeared a little oversimplified when the results gave United States unprecedented power and dominance in world affairs.  The effects and consequences of this war were probably a big surprise for the United States too as it suddenly found itself at the apex of a bipolar world. 
Consequences of the World War II:
On the surface it might appear that World War II was fought for a great cause since its purpose was so clearly defined. But a clear understanding of the effects and consequences of war would make people think twice before falling for such simplistic view of Second World War.
Some of the key consequences or effects of this war are summarized below:
World War II resulted in 50 million casualties  with 400,000 deaths in the United States alone
It negatively affected the economic conditions of the countries involved
It shifted balance of power in favor of the Allies and divided the entire world into two sections i.e. those who supported the United States and those who did not.
While the economic boom of 1950s was enough to make the government and people forget about the immediate negative impact of the WWII, still economic analysts maintain that this second Great war had done more damage to economic structure of the United States than was previously known. Immediately after the war taxes were raised to cover the cost United States government had incurred to secure victory in this massive military conflict. If estimated in 'current terms', the cost would come close to $350 billion.  Richman (1991) writes, "It was World War II that made the income tax the mass tax that it is today. Five million people were added to the tax rolls during the war." 
Since the federal government had limited fiscal power prior to the Second World War, the only way to expand it was levy more taxes. This continues to be the major feature of American fiscal policy even in the 21st century.  Gerber (1995) writes, "Even at the peak of the New Deal, relatively few Americans were subject to the federal income tax. The tax base for the federal government remained so small that Washington had only a limited capacity to influence the overall performance of the economy. In 1939, fewer than four million Americans paid federal income tax. Before the war ended, that number had increased to over forty-two million, and the dollar value of taxes paid by individuals had increased nearly twenty-fold." 
But America did not suffer as immensely as some European countries did in the post-war years. This was mainly due to the investment made by the government in the Defense sector. These fiscal measures helped in reviving business and government shifted its focus from external problems to internal ones. Returning servicemen required monetary aid to rebuild their lives. Government enacted Servicemen's Readjustment Act of 1944 which 'eased the transition from military to civilian life' by providing loans to servicemen. 
These investments increased money supply in the market, which gave a major boost to economic activity in the country. And hence Americans witnessed the economic boom of 1950s, which erased the unpleasant memories of WWII to certain extent.
In World War II, United States government tricked people into believing that it had chosen to stay neutral at all costs so that American soldiers wouldn't be forced to fight a foreign war. However President Roosevelt failed the entire nation when he pushed his soldiers into this military conflict only to expand its influence and declare itself as the new superpower. Not only the government took advantage of naive American public's blind faith in Roosevelt's policies, it also unfairly used its military might to dethrone former superpowers.
To this day, most war analysts and historians maintain that Hiroshima/Nagasaki attacks were totally unnecessary. Dwight Eisenhower, commenting on these attacks, said."..the Japanese were ready to surrender and it wasn't necessary to hit them with that awful thing."  These attacks exposed American Army's unethical war practices and policies and warned to the world that United States had joined this war for a reason other than maintenance of peace in Pacific region. Ellis Zacharias, Deputy Director of the Office of Naval Intelligence, confessed, "I submit that it was the wrong decision. It was wrong on strategic grounds. And it was wrong on humanitarian grounds." 
Such events of WWII played a crucial role in changing the shape of world politics. United States government was aware of the opportunities that this war presented and wanted to seize them at…