In the world - and universe - of Pandemonium, humans have existed for thousands of years in parallel to humans on Earth, having crossed over during periodic collisions between Pandemonium's universe and our own.
In Pandemonium, humans have been genetically engineered for thousands of years. The first humans that were genetically engineered became separate species, but in the last couple of thousand years, the technology of genetic engineering has improved to the point where carriers are human and engineered genetic traits can be passed down by adding a special extra chromosome.
These extra chromosomes can be programmed to duplicate themselves if they are the only chromosome in the resultant fertilised ovum (thus passing themselves on to all offspring, even with an unengineered partner), or to delete themselves if they are the only one, if they find themselves in the presence of an incompatible chromosome, or if they find themselves in the presence of a 'delete' or the absence of a 'retain' molecule.
Genetic engineering of humans has progressed to the point in Pandemonium where in modern times, roughly 75% of the population carries genetically engineered traits. Most unengineered humans are concentrated in nations where genetic engineering is frowned upon, and in nations that support genetic engineering, around 90% of the population carries engineered traits.
Some of the engineered traits that are particularly common are radio horns (as in Why would radio-capable transhumans still vocalise to each-other?), gastric bypasses (as in Uses for a gastric bypass), variations in skin and hair colour that make colours such as red, green and blue possible, and artificial genes that make their carriers more attractive and less prone to conditions such as obesity or anorexia.
Many of these engineered traits were imposed upon the offspring of well-to-do people who wanted their descendants to have advantages that they themselves did not possess, and could not possess since these traits cannot be imposed except from conception.
On the world of Pandemonium, wars are about as common as they are in our own world, which is to say that minor wars occur somewhere in the world almost every year, but major wars are a once-in-a-generation thing. The mechanical technology of warfare is somewhat more primitive than on Earth, with muscle-powered weapons and animal-mounted cavalry being common, and rifled muzzle-loading guns being state of the art, though there are also soldiers trained as 'magicians', who can make use of magic engines (as in Practicality of engine-mediated magic).
So, to my question: In this world, would it make sense that governments (as opposed to private individuals or families) would mandate the genetic engineering of a caste of soldiers to make them better able to survive and prevail upon the battlefields of Pandemonium?
Answers should consider likely genetic modifications with battlefield utility, their utility and liability in society between wars, the potential for genetic espionage, and the implication that those with government-mandated war-genes would be expected to be soldiers, even if it was their ancestors who signed them up for the gene mods.
EDIT:
I'm concerned with governments that we would call liberal democracies. Yes, there would be dictatorships, and they'll do just whatever they want, but they don't concern me, just the liberal democracies.
As for levels of mobilisation, we could consider WWII levels to be the maximum for the aforementioned liberal democracies.
As for the sorts of mods possible... pretty much anything goes, as long as the end result is still sufficiently human to be functionally human and scientifically plausible... and justifiable to the populace.
