What is power? To answer that question, we might first ask another: Why does anyone want power? The answer is plain: actors need power to get what they want. Power is a means to an end. Whether that end is security, honor, wealth, all the above, or something else entirely, power is how actors achieve their aims. If we are to recognize who gets what they want and why, we need to define power and understand the ways one might attain it. We first need a clear definition of power, to consider other prominent definitions in light of that definition, and finally to find a way to adequately operationalize that definition to aid our understanding of power international relations.
The components of power in international relations are myriad. Material resources including military assets, natural resources, economic capital, demographics, and geography all contribute to national power, as do other less tangible aspects such as diplomatic skill, military effectiveness, culture, or national spirit. Together, these building blocks form a power base that actors can use to get what they want. Mere possession of the blocks, however, does not guarantee power. As Jeffery Hart puts it, “reasons for controlling resources or other actors arise of the desire to achieve certain outcomes.” States must also, therefore, be able to convert their base resources into outcomes. Without the ability to do so, they squander resources, diminish their power, and fail to get what they want. Considering these facts, this is our definition of power: A’s ability to convert its capacity into getting what it wants.
The two-part definition is essential to capture the key elements of power, each of which merit closer attention. Each part of the formula depends on the other. First, resources – capacity – are necessary for any exercise of power. As Joseph Nye argues, “Power is conveyed through resources, whether tangible or intangible.” A country with more resources, be they tanks, bodies, dollars, or skills has a greater capacity, or potential, for power.
But as our definition implies, capacity is not enough to be powerful in a given situation. Nye again: “Power conversion—getting from resources to behavioral outcomes—is a crucial intervening variable. … because it is outcomes, not resources, that we care about we must pay more attention to contexts and strategies.”  In other words, actors must use effectively the resources they have to get what they want. This is often more difficult that it might seem. Nye points, for example, to America’s Vietnam War as a salient demonstration of that fact. The United States, with a far greater total power capacity than North Vietnam, could not convert its tanks, planes, bombs, bodies, dollars, and influence into the outcome it wanted. The United States failed to achieve power. In such a case, A might have a greater total capacity for power than B, but A fails the second half of our power formula. A does not, or cannot, convert that capacity into getting what it wants. B, meanwhile, might successfully convert its lesser total capacity into getting what it wants. In this case, B has exercised power over A.
This broad, outcomes-based definition of power accounts for the different kinds of goals different kinds of actors have. Not all states seek primacy; some desire to simply maintain an acceptable economic and security environment. As Hart argues, outcomes provide the best approach to power because a power conceptualization based on outcomes is both more general than others and accounts for interdependence among actors. In this way, it’s an improvement over Robert Dahl’s much-accepted definition that “A has power over B to the extent that he can get B to do something B would not otherwise do.” While Dahlian power is one important aspect of power, as a concept, its scope is too specific and excludes too much. As discussed above, A getting B to do something does not mean A gets what it wants. Furthermore, a broad definition of power is better able accommodate states with less power or those looking to “exploit asymmetry” like Vietnam, states that want to get B to not do something, and states trying to maintain their regional position or standing in an interconnected balance of power. Power may be relational, but relationships are more diffuse and interconnected than Dahl admits, and a complex, multi-state environment makes Hart’s outcomes-based approach superior to Dahl’s.
Dahl’s definition is not without its uses, however. We should think of his narrow concept of power as one of those all-important strategies that complete the second half of our power formula: converting capacity into outcomes. Dahl’s is one conversion strategy and the first of Steven Lukes’s three faces of power. Each face, in fact, offers a different strategy for converting resources into outcomes and fits comfortably into our broad definition of power.
In the first face of power—Dahl’s kind of power—A demands B do what A wants, “your money or your life,” as Nye describes it. Either by threats or inducements, A tries to get what it wants from B. Naked power carries a real risk of failure, and also requires using up resources, which might leave a state with less total capacity for power and nothing gained. Still, this power conversion strategy is the most basic and underpins the other strategies, even if just implicitly.
This narrow route to power is not the only one, it is only the most direct. There is a subtler method of converting capacity into outcomes. This is Peter Bachrach and Morton Baratz’s second face of power strategy, wherein actors “influence those community values and political institutions … which tend to limit the scope of actual decision making.” As Nye explains, powerful actors can use their power to make sure other actors don’t get a seat at the table or, if they do, must abide by rules limiting their choices already implemented by the powerful actors. A might spend its resources to build institutions or international orders that set agendas and constrain B’s choices so that A gets what it wants. If B accepts A’s order as legitimate, A can get what it wants with less risk and “save on carrots and sticks”.
Lastly, Steven Lukes argues the best way actors can exercise power is by shaping the initial preferences of those around them. If A can reshape a situation in a way that causes B to want what A wants, it is no longer necessary to override B’s initial preferences, either by constraining the agenda or by resorting to force. A and B now desire the same outcome and can add their resources and conversion skills together to get what A wants. A can convert B’s own capacity into A’s own desired outcome. As Lukes says, what better way to exercise power?
Although an outcomes-based definition of power is the most accurate and encompassing, operationalizing to study international relations can be difficult. We may look backward through history at different actors, assess their capacities in terms of resources, and ask for any given situation: “What were their goals? To what degree did they achieve them? And how?” In this way, we might analyze the power of specific actors at various points in time by determining if they were able to convert their capacity into desired outcomes. By drawing careful and appropriate analogies from history, we might understand which resources are important in which situations, which conversions strategies work and when, and we might apply those lessons about power to the world before of us.
This operationalization, however, is too constrained to satisfy all international relations scholars. Here we must admit that an outcomes-based conceptualization of power is difficult to operationalize in a predictive manner because it is issue specific. With it, we cannot draw up a hierarchy of power in the world today, for example. What we can do is estimate the total amount of capacity each state has at its disposal. To best operationalize our outcomes-based conception of power, then, we should turn to Michael Beckley. Beckley admits that a power-as-outcomes approach such as ours “measures power to a greater degree of granularity,” but in order to predict power in the present or future, the best we can do is account for the net value of resources an actor has at its disposal. By doing this (Beckley’s GDP method is a workable proxy), we can at least understand a state’s approximate total power capacity and fill in the first part of our two-factor power formula.
In this way, practitioners of international relations can not only grasp the rough distribution of power capacity in the world, they can also combine that estimate of raw power with an understanding of historical power conversion strategies and apply that hybrid knowledge to specific ongoing or potential conflicts. Still, it must remain obscured in the fog of the future whether the actors will successfully use one of Lukes’s faces of power to convert their resources into getting what they want. Power is never assured.
 Hart, Jeffery, “Three Approaches to the Measurement of Power in International Relations,” International Organizations, Vol. 30, No. 2 (Spring 1976), 296.
 This definition has its basis in Figure 1.1 in Joseph Nye’s The Future of Power (New York: PublicAffairs, 2011) 11.
 Nye, Joseph S. Jr, The Future of Power (New York: PublicAffairs, 2011), 8.
 Nye, The Future of Power, 11.
 Hart, Jeffery, “Three Approaches to the Measurement of Power in International Relations,” International Organizations, Vol. 30, No. 2 (Spring 1976), 303.
 Dahl, Robert. “The Concept of Power,” Behavioral Science, 2:3 (July 1957), 202-203.
 Hart. “Three Approaches to the Measurement of Power in International Relations,” 292.
 Dahl, “The Concept of Power,” 202-203.
 Nye, The Future of Power,11.
 Bachrach, Peter, and Baratz,, Morton, “The Two Faces of Power,” American Political Science Review, Vol. 56, Issue 4 (December 1962), 952.
 Nye, The Future of Power, 14.
 Ibid, 16.
 Lukes, Steven, Power: A Radical View (New York: Palgrave Macmillan, 1974), 29.
 Nye, The Future of Power,
 Beckley, Michael. “The Power of Nations: Measuring What Matters.” International Security, Vol. 43, No. 2 (Fall 2018), 12.
 Ibid, 12.
 Ibid, 14-15.
 Ibid, 21. Beckley multiplies total GDP by per capita GDP to approximate the net resources at a state’s disposal. It’s not a true net, but it works well enough for our purposes.