A recurring observation in Marx's critique of capital is that capital seeks to ceaselessly expand, and upon coming up against obstructions to its expansion, it must surmount them or descend into crisis. One simple example of this occurred early on in the processes of industrialization, when the industrializing nations were still relying on biomass for energy, and so the open land required by wood fuels conflicted with pasture land and agricultural land. This obstacle was surmounted first with coal mining - going underground as opposed to outward - and then the transition to oil, which could also be extracted from the earth, saving the valuable horizontal real estate for agriculture and development.
Of course now we're coming back to this problem full circle, with the enormous amounts of open land required for renewables and biofuels to replace fossil fuels at scale.
Keeping this principle in mind, and moving from the economic realm to the military realm, one of the more interesting theoretical constraints facing the modern world now, as it moves deeper into an era of warfare, is the actual production of soldiers. We saw early glimpses of this with the United States running into problems during the broadly unpopular Vietnam War, when public trust and state legitimacy dropped to a new low and draft dodging was at its peak. The draft was retired after the war ended, partially because the state had determined that there was enough manpower for military supremacy without it (we'll get back to this).
Civilization itself has had a long history of contention over drafts and conscription. This was one of the cardinal issues facing imperial Rome as its military expansion faltered, beset by declining populations chewed up by endless war, civil war and plague, and many of the traditional stock had been hollowed out by the creditor class - soldiers had to own land and be wealthy enough to bring their own equipment - so the military was professionalized and drew more heavily on mercenary forces and eventually the Germanic tribes for its stock.
The various other historical reasons are quite complex and context sensitive, and at the moment I wanted to get at a more contemporaneous problem, so I'll briefly sketch that out now. More recently Russia experienced this problem with its "partial mobilization." Before the mobilization, there was a certain uneasiness in Russia regarding the war, but large swathes of the urban population in particular were able to go about their day as normal, ignoring the war as an abstraction in the distance, which was something we also experienced here in the States as the Iraq war grinded on: a reality for only a professional and mercenary minority and its distant foreign victims, with much of the population learning of the war as an abstraction represented by news reports, themselves carefully manufactured of course.
When the prosecution of the invasion started to bog down, and Putin launched the partial mobilization, there was a panic especially throughout the professional classes, and lots of people jumped across the border to avoid the mobilization. The state was able to meet its mobilization quota, but it also revealed the underlying weakness of the body politic when it came to supposed matters of "national survival."
This is a problem for advanced imperial states in particular: military supremacy in the modern age correlates with economic supremacy: one has to climb the value chain and command powerful military technologies and a formidable industrial apparatus to keep up with the top military powers.
There was an inflection point in which this became more true: in the ancient world population booms and cultural military innovations like mounted cavalry and horse archers could tip the scales on the battlefield, but once technologies like firearms and artillery appeared on the world stage, in which a large amount of destructive power could be marshalled without high skill and training (though there is always some required), and the democratization of the warrior class and mass armies came into the field, the center of gravity shifted to the economic realm in which technological innovation and efficiency of mass production came to the forefront in battlefield supremacy, showcased dramatically in the shocking industrialized meat grinders of the theaters of WWI.
So a given military power that wishes to be formidable must industrialize and intensely develop its urban environments as a result. Modern industry requires the density and efficiency of the modern city to sustain and grow its economic activity with forward momentum. Further, the modern value chain is a creature of incredible complexity and breadth, so a given power must source materials, knowledge, and technologies on a global scale, developing the cities into world cities in the process.
What this ends up doing is cutting into the stock which is traditionally associated with warfare, and there are complex reasons for this. What modernization and urbanization typically do is create larger and broader classes of professionals with raising living standards, who are also better suited to utilize global transportation networks and global energy flows to physically move rapidly with ease. The prototypical middle class - at risk of striking a crude generalization - is a class literally raised above the soil and away from the soil's concerns, plugged into the rapid-moving global industrial energy flows and taken up into them.
Conventional warfare is a more visceral activity with a more intense physicality, and it is also one of certain death, which is why the stocks are more intensely drawn from poorer and more rural regions, populations less able to move away from danger with ease and which are accustomed to more physically violent daily realities . There is a contradictory bottom limit to this as well: a population can't be grinded down into dust to produce soldiers either: for a decent physical constitution, good nutrition is required and some education to manipulate and navigate the increasingly complicated infrastructure, transportation, instruments, and tools of modern warfare.
As a nation's wealth grows, and the broader that wealth is distributed, the more physically mobile and autonomous its population becomes, while at the same time becoming more integrated with and dependent on the global industrial system. The reality of the geographically bounded nation itself becomes more paradoxically abstract as a result, and the ever-shifting mirage of global industrial prosperity becomes ever more real. Global capital, with its absurd concentrations of power and disposal of incredible stores of energy, can flit to and fro to wherever is advantageous, extract what resources it can for as long as the host remains amenable, and then up and leave when it gets too hot or bothersome.
The fear of the modern state is a host's fear of the irritated businessman. In the modern age it has become more difficult to simply strongarm one's population into submission: doing so risks the ire of the global industrial system and economic and political isolation and the ensuing capital flight. One must balance throwing one's weight and assets around while remaining open enough to allow the steady passing through of globally sourced resources and capital, like controlled wind through a musical instrument. So we see the constant nervous courting of capital, the hopeless reliance on debt and bondholders and desperate promises of austerity, the prostrated deregulation of markets and privatization, and so on.
This of course was an ephemeral attribute of the golden age of globalized capital, which peaked alongside the peak of high ROI oil, and which becomes further and further threatened as constraint grows with dwindling available resources and heightened international tensions. At the same time, there is a countervailing shift to re-territorialize the functions and activities of the modern state and economy: a tightening of borders and the return of industrial policy, as the global system becomes increasingly strained under a multitude of pressures within and without, which still must be balanced with the need for global trade and access to a complex array of resources and labor from many different regions and specializations, a contradiction that is beginning to make itself shown in the bifurcating trade blocs.
Back to the actual labor stock itself. Mirroring the more general labor question, in warfare too there is an inclination towards greater mechanization and automation to offset the problems created with a modernizing and urbanizing population. What the US military realized with Vietnam - though the war itself was a complete failure - was that with rapidly advancing aviation, targeting, munitions, and communications technologies - to just name a few - it was possible to use less and less human operators to achieve more and more destructive power, so that the increasingly politically troublesome draft was no longer necessary.
We know especially with the history of modern warfare in the Middle East that this dream of automation was more pipedream than guiding ideal, but the belief itself does matter quite a bit for ordering larger scale behaviors. Its highly probable that with more and more sharply constrained resources and a growing instability of the world system, that that coveted human soldier stock will become more important again, but it is hard to tell how long that will take.
