Every great power has its share of decisive victories which led to its dominant position, and so subsequently goes on to pine for additional short, sharp victories in the future, eventually hubristically lodging itself into a protracted conflict it can't win, or which seriously damages it in some way. This is a tendency that is probably as old as warfare, as one can imagine. The United States has shared this very fixation since the Civil War.
The Germans called their preferred short wars "Cabinet Wars," and then in a fatal miscalculation, were undone in what they referred to with dread as a "People's War," when they were caught in the World Wars, as Big Serge brilliantly detailed in a post. That dreadful People's War more resembles a wildfire that is touched off by a campfire getting out of hand, in which an entire country is moved to wrath over what should be a localized and contained conflict, bringing into question just what conditions are required for such a terrifying turn of events.
Leaps in mobile armor technologies, like the tank, and advances in aircraft capabilities helped to break large armies out of the trench rut in WWII, though trenches reappear for various reasons in various theaters after that, most notably today in the Russia-Ukraine War.
Most immediately, in a bogged down conflict such as this, one of the most important winning factors is sheer economic power, or more specifically, manufacturing power. As Ben Aris put it in a fascinating War Nerd Radio podcast on the economic side of the Russia-Ukraine War, trench warfare tends to progress towards a material attritional conflict: both sides in trenches, unable to clearly see each other and get at each other, have to simply launch more and more quantities of artillery shells over to the other side, with the aim of sustaining more and more casualties on that other side. He continues on: with 1 - 5% casualty rates in the trenches, the combatants can fight on, but as the rate climbs up to 30%, morale starts to break down. Under this calculus, fighting power translates to manufacturing power: the production of artillery shells. And it has become clear that Russia's war economy has been rapidly ramping up, while the West's - which backs Ukraine whose industry is in ruins - industry is sputtering out, laden with sclerotic plutocratic operations.
Such a conflict more resembles two stags or bulls locking horns in order to continue fighting without necessarily goring each other. But then, as history has shown us, these bogs grow deeper. They pull in more resources as each side engages in deeper commitments to sunken costs, and soon enough the entire landscape - which had been growing ever more parched and desiccated and sullen - is lit aflame. And then the goring happens anyway. Indeed, we're seeing that now in a more distributed manner, in the growing conflicts springing up across the globe, and the economic tensing and winding up and attached and growing geopolitical tensions.
