Many thanks for all opinions and experiences shared in here so far, also for great photography additions of few guys! Interesting to read different point between various military or ex military guys.My initial intentions were not exactly to compare pro's and con's of folders vs fixed in the battlefields or on everyday soldier's duties, however two major groups emerged here, one that see fixed blade on duty as necessary while other group not and rather opt for folders/multitool...i don't mind the way thread evolved, as all additions are at some point related and discussion goes well and informative so far.
I personally believe that military personnel shall be definitely equipped with fixed blades, regardless of climate.It doesn't matter whether soldier find himself in desert warfare or deep jungle, neither matters if technology have great impact by increasing distances between oppositions on battlefield, one is very likely to find himself in urgent need of tough, capable blade for many unforseen reasons and such a tool can become quickly only lifeline and saviour of human life in critical moments,or just simply utility tool for task,where folder wouldn't do the job as effectively or at all...However, I think that for most of the ordinary days of soldier, good folder or multitool, will cover pretty much nearly every task without need of fixed, tougher blade.
When it comes to deployments in some specific climate conditions such as mountains with thick vegetation and woods, or tropical jungles - where soldiers are practically living and serving daily in close proximity of many dangerous wild animals night and day plus having to work their way through thick vegetation or build shelters occasionally, or mask the artillery, vehicles etc,setting trapps for enemy / animals when running out of food, good reliable and sharpened blade, (not only machetes) is a must IMO... In these conditions, multitools or folders obviously wouldn't much help as "only edged" tools.
Again, - I wasn't deployed into any warfare, serving only mandatory military service in middle of Europe,so i can not fantacise about topic much, but i can imagine, I d definitely had more than one knife on me,if I would be the only guy from entire battalion, to carry fixed blade, i d be the one!!!,,,, and I would invest into my optional knife best as i could,(not overly) but definitely wouldn't be saving on it. Knife would have to be able to hold much more than my bodyweight in lateral strength, easy to sharp, be an all rounder, not too large but neither too small,able to chopp, hack, slash,stab,batton,with some level of rust resistancy,simply reliable and well functional in most tasks expected from good combat knife.Also would carry back up fixed blade, plus folder for day to day use.
Mankind evolved tens of thousands years along knife - this tool was and still is of great importance for every human being and I think soldier have twice as many reasons to carry it on his route to unknown.