Presidential Leadership and the Creation of the American Era, by Joseph Nye, though focusing primarily on the foreign relations role of the president and how presidents over the last century have helped to shape the United States' position in the world, provides great insight into the role of individuals in shaping the institution of the presidency itself. Nye's work is at the centre of a debate that could be characterized as the political science equivalent of the nature versus nurture debate. For us in political science, it is more generally a debate whether it is environments or individuals that have a greater influence on policy outputs and outcomes.

In discussing how America got to the position of power it held in the world at the close of the twentieth century Nye begins with the question, “What role did individual leadership play?” (6) In other words, was the creation of “the American era” a matter of environmental happenstance, or did the individuals who held positions of leadership—presidents in particular—play a role by the choices they made? While cautioning against leader attribution error, Nye also points out that leaders can create their own (and their country's) opportunities. He writes, “Sometimes leaders not only take a fork in the historical road but help to create it” (5). The question remains, however, if the fork taken or created is the correct one.

Nye notes a definitional problem with a well-used term, developed by James McGregor Burns (1978): transformational leadership. The problem for Nye in using this term is its juxtaposition with the concept of transactional leadership. For Nye, the term terms are somewhat limiting. Instead he continues the Burns usage of transformational or transforming leadership having to do with the expression of lofty goals but creates a matrix of leadership objectives and styles. In doing so, he differentiates between leaders with transformational objectives and those with status quo/incremental objectives as two different types of leaders. The other axis is based on style: transactional versus inspirational. This differentiation between objectives and styles allows Nye to delve more deeply than he would be able to by using Burns' older construction. For example, Nye categorizes Harry Truman as having transformational objectives combined with a transactional style, Woodrow Wilson as having transformational objectives and an inspirational style, Dwight Eisenhower as having status quo/incremental objectives and a transactional style, and Bill Clinton as having a status quo/incremental objectives and an inspirational style.

It is not the entirety of presidential history that Nye covers in his analysis. Rather, he looks at the development of the “American era” from Teddy Roosevelt through George H. W. Bush and further focuses on key presidencies in that time frame. Nye selects those presidents “who presided over the four positive phases of the expansion of American power in terms of their effectiveness and ethics” (20). Thus, he admits to leaving out those presidents who did not preside over the “positive phases.” In some ways this limits the extent to which we can infer the importance of leadership, though it could be argued that it was the presidents who drove the expansion of American power and if they didn't make Nye's cut, their leadership was lacking. This selection of presidents does not diminish the overall point Nye makes that individuals do matter. The skills, the personality, the outlook of the individual in the office are causally related to the outcomes. The key is in how they bring those factors to bear on the situation before them.

Much of the difficulty that Nye points out for presidents in the latter portion of his time frame coincide with what many scholars have referred to as the postmodern presidency or what I prefer to think of as the imperiled presidency. This is a period of time when the presidency has been more vulnerable to attack by the media, by domestic political opponents and by foreign powers (at least metaphorically or rhetorically). It is in this period that one could argue that the characteristics of the individual matter most. Nye writes, “Presidents will face an increasing number of issues in which obtaining our preferred outcomes will require power with others as much as power over others” (159, emphasis included). A president's skills as a politician on a large stage will be ever more important and he or she will have to adapt to an ever-changing environment, including the relative power position of the United States with respect to other governments and organizations in the world. Nye concludes that at the very least, the individuals who have held the office of president have played a significant role in the creation of the American era. He notes further that since we are in an environment where America is no longer the sole power, presidents must “develop contextual intelligence” (159) to understand that though the United States is still perhaps the most powerful player, it now needs the co-operation of others to achieve its goals.