20th Century Research Paper

Few argued when the 20th Century was dubbed the "American Century", a term first coined in the early 1940s when the country was still overcoming its isolationist instincts. Over the past 15 years, America's fortunes have changed with dizzying speed. First came the tremors: the dot-com bust and a disputed presidential election in 2000. Then came the massive convulsions: the destruction of the Twin Towers in 2001 and the collapse of Lehman Brothers in 2008. Long wars in Afghanistan and Iraq have exacted an enormous blood price - the lives of 6,852 American military personnel - not to mention immense financial expense, estimated to be as high as $6 trillion (£3.9tn). The detention centre at Guantanamo Bay has undermined American ideals, just as the NSA and WikiLeaks spying scandals have undercut American diplomacy.

George W Bush, a president with a Manichean worldview, was widely seen as over-eager to project America's military might, without adequately considering the long-term consequences.

Barack Obama, who campaigned in 2008 on a platform of extricating America from its unpopular and exhausting wars, has drawn criticism for disengaging too much. Under both presidents - the first an impulsive unilateralist, the second an instinctive multilateralist content sometimes to lead from behind - America's global standing has been diminished. Polls regularly show that Americans recognize that their country's international standing has waned. Among the young, this trend line has fallen sharply. Only 15% of 18-29-year-olds believe that America is the "greatest country in the world", according to Pew, down from 27% in 2011. Tellingly, however, there has been no great public outcry. No longer is there much appetite for America playing its long-standing role of global policeman, even in the face of the rise of the group calling itself Islamic State. The cost, human and financial, is considered too great. Americans increasingly think that other countries should share the

burden. Obama, while continuing to trumpet "American exceptionalism", regularly prefaces remarks on foreign affairs by acknowledging the limits of US power, again with little public outcry. Assad's flouting of American warnings is especially noteworthy. In killing so many civilians with chemical weapons, he flagrantly crossed the "red line" imposed by Obama, but escaped punishment. The president was unwilling to carry through on an explicit threat, in what was the biggest foreign policy climb down of his presidency and also one of the most significant in the past 50 years