[For an explanation of this posts purpose see this post and this second post explaining the observer.]
The 21st century opened with one of the most atrocious terrorist attacks of all time, which occurred on September 11, 2001. This was an attack motivated and conducted by a reactionary Islamist ideology and organization called al Qaeda. This organization was a radically decentralized network wholly independent of state control, its emergence was the first sign that the monopoly of the state on international politics had decisively ended. While it would be many years before the more general proliferation of networks of comparable scope and influence, the general outline of the future success of this form of social organization could be seen in this first, evil pioneer. The attack itself, which still remains among the largest and most destructive terrorist attacks of all time, caused relatively little physical damage, at least when compared to the devastation elicited by the response to it. However, the social and cultural scars ran much deeper than the physical damage. Despite the essentially social and cultural nature of the attack and the motivation behind it the US government acted in a state-centric matter. Rather than seeking to engage and defeat its opponent in the social and ideological sphere in which al Qaeda existed, operated and acted, the US instead conducted invasions of two states in an attempt to destroy al Qaeda's material base of support. This approach would prove ultimately futile, though it did succeed in shifting the focus of what was then called the “war on terror” into Asia, and it would be some time before the US, or other states, would realize their inability to counter this form of threat and develop institutions capable of effectively countering them.
This opening act of the 21st century would unfortunately set the tone for its first half. Over this period the US would decline from its position of hegemon to simply being one of several great powers. This was not a predestined end, at the beginning of the period the US had all the capabilities it needed to create the conditions that would have led it to being first among equals today. However, from its position of dominance the US was unable to appreciate the changing role of the state in a world in which non-governmental actors played an increasingly prominent role and several powers existed on a continental scale. Benign neglect would characterize the US's attitude to some of its key initial advantages and its unprecedented military might gave an exaggerated sense of its ability shape the world. While the US entered the period unchallenged its shifting focus towards non-state threats would open up space for the rise of other military challengers, particularly ones that more quickly adopted doctrines that could leverage non-traditional political organizations and military tactics. What is surprising is that even after the Cold War in the latter half of the 20th century, where the US engaged in a low level conflict with the Soviet Union primarily through economic, scientific, and cultural competition with only intermittent military struggles conducted mostly through proxies, the US had not yet fully come to terms with a world of several continent sized powers and that this world had intrinsic differences from one dominated by the small and aggressive states, which characterized the world before WWII.
Domestically, the US was riven by deep internal divides. Its two main political parties remained locked in ideological battles over ideas that had been largely exhausted during the 20th century. Its curious to a modern reader to see political debates dominated by terms such as "socialism" and "capitalism" or the heated debates over the role of the state occurring even as what was then called "globalization" and the rise of non-western powers fundamentally changed the state's role. The absence of debate over reforms necessary for the US to prosper in a world that even then looked radically different both from the world of the Great Depression and WWII that gave rise to the period of American hegemony and from the Republic's early origins is striking. There was little recognition in the political culture of the early 21st century US that the world they lived in could no longer be understood in terms of capitalism vs. communism or even democracy vs. authoritarianism. The world had moved on, US political culture had not.
Combined, the persistence of antiquated political concepts and anxiety over social decay would render the US incapable of responding to the long term challenges it faced. Structural challenges, both domestically and internationally, required strong, innovative leadership. The political and social constraints of the day rendered the US incapable of generating this leadership, conventional thinking was rewarded by the unreformed electoral system giving the US a string of poor to mediocre leadership at a time it could ill afford it.
A major source of gridlock was that national representation existed only at the executive level, the legislature would not have Senators or Representatives at Large until the 28th amendment. Without this level of representation politics remained dominated by concerns at the local level. Poll after poll showed that citizens disapproved of the actions of both parties at the national level but were satisfied with the performance of their own legislator due to local concerns. Without reform it was impossible for national voters to hold accountable legislators and parties since they could rely on their local base to resist the will of national majorities. Legislative politics was dominated by the ability of legislators to get “pork” for their local district, with no national representation to provide a check on this incredible amounts of waste could pass through the legislature without organized opposition and projects of clear value to the nation could not muster support since many of these projects lacked a local constituency in a sufficient number of districts to gain support from parochial legislators. It was not until the US was clearly falling behind other states with a clearer mandate to set policy at the national level that a political coalition was able to deal effectively with gridlock. This gridlock also led to a high level of partisanship that further paralyzed the legislature and prevented a realistic assessment of the nation's needs as each side attempted to blame failure on the beliefs of the other side.
Many issues that could have been relatively easily dealt with, and that were seen at the time, languished due to these problems. Today, we can still see the results of the inability of the US to deal with them when it had the power and opportunity to do so. The linked issues of terrorism, global warming, and infrastructure decay is probably the strongest example of this. The costs of global warming could have been mitigated cheaply during this period if the US had engaged in a national effort to head it off. The huge funds flowing to underdeveloped middle eastern states that played such a powerful role in the development of non-state actors that would play such a strong role in undermining the traditional powers, with al Qaeda being the pioneer, may have been preventable if a shift away from oil had cut these funds off sufficiently early in the period. Investments in infrastructure at this time would have reduced the financial strain of later decades if it had been done in the opening decades rather than when demographics posed such a strong strain on finances in later decades. These efforts may have also given the US the credibility and influence it needed to retain its predominant international role. Would things have been different if the US had been able to act more decisively as a nation and prioritized using its influence to integrate rising powers into the world system it had created over its unilateral action to attain shorter term goals?