I've always had the urge to define national power in quantitative terms. Many histories strike me as overly wishy-washy due to an insufficient grounding in numbers. Not only does this hamper understanding, but it also presents a considerable challenge in terms of wargame design.

One scholarly effort to that effect is the "Correlates of War" project. It defines "power" as "the ability of a nation to exercise and resist influence - [...] a function of many factors, among them the nation's material capabilities."

Said material capabilities are measured by the CoW project result in the Composite Indicator of National Capabilities (CINC):

CINC =

TPR = total population of country ratio

UPR = urban population of country ratio

ISPR = iron and steel production of country ratio

ECR = primary energy consumption ratio

MER = military expenditure ratio

MPR = military personnel ratio

Making use of the readily available CoW data sets, I've come up with the following chart:

Some claim the 21st century will be another American rather than say Asian century. Similarly a common trope in US election campaigns is that "America's best days are yet ahead". I trust in absolute terms, that may very well be true. But in relative terms, the United States is on a (soft) downward trajectory.

The CINC however weights population and military personnel figures too highly. As such, I'd say it's overly biased towards continental giants such as China and Russia. Their technological backwardness for much of the past two centuries is insufficiently factored in.

For wars are good tests for the reliability of such indicators as the CINC. Take the Sino-Japanese War of 1894/95. The CINC would suggest China won. One might say  that the CINC is more geared to POTENTIAL rather than ACTUAL strength.

So I'm tempted to work out an alternative capabilities index (one that works for the industrial age I'm most interested in, at least). Scholars have tested such models against "power transition" phases and the like. Too mathematic and arcane for me. I mean to drop the total population and military personnel figures from the equation and see whether then the results look reasonable and intuitive.