Sadly, fiction has ironically become reality one way or another given modern human history. Given humanity's oh-so-long rap sheet when it comes to inter-ethnic conflict, I wouldn't be surprised that things go down that road. We've got way too many ideologically charged 'idiots' and madmen who want to 'bring humanity down to size' and 'make humanity humble', to 'settling scores' between ethnic groups, or the more common 'exterminate [insert ethnic group here], utopia happens' line of thought.Right, I remember why I don't like you.
You're psychotic.
Genocide Man territory jesus fuck.
Keeping nation-states actually stable is beyond brutally hard if enough idiots can whip up horrible syth-plagues or worse every few days or less. The US Intelligence Community puts the ability to create synthetic plagues and gene-editing proliferation on the top end of it's watch lists. Operation DARK WINTER played with a 'worst-case' planned plague scenario back in 2001/2002, and have planned extensive countermeasures just in case it actually happened. Hell, you don't have to infect humans either, to really do some damage you can simply whip up something that breaks a binome (called 'binome crashers') and let mass starvation do the rest.
We've literally got the tools to eliminate disease, but those same tools can be easily re-purposed into weapons.