The difference between 1915 and 2015 is that we've improved the industrial scale machinery of killing to a point that it is too powerful. No two top 10 states can really fight each other, because nuclear exchange will ensue and the consequences of that are too unpredictable and high risk to engage in.

So we engage in proxy conflicts in the periphery and kill the hapless inhabitants there. There's no "battles", but lots of death... Mostly of people that are inconsequential to whomever is writing the history.