Wait what? Those expensive machines make war harder, not easier.
Central African Republic has war with child soldiers using machetes and guns. It's an unpleasant truth: humans are disposable.
This is evidenced by a bunch of stuff - rich westerners have their clothes made by poor people locked into unsafe Bangladeshi warehouses; have many of our goods made by low people in terrible and dangerous conditions; by our lack of interest in garbage pickers or street children or etc.
I suspect (but cannot point to hard numbers) that machines might actually be cheaper if you are (politically or otherwise) forced to look after your human soldiers to a reasonable standard, especially in 1st world countries.
Consider the initial training expenses, equipment, career-appropriate salary along with possibly reenlistment bonuses, along with (in the worst case) medevac, multiple complex surgeries, and lifelong treatment/disability pension for some injury. Not to mention the logistic costs of transporting them to various places around hte world, and maintaining an acceptable standard of living there.
Per-machine costs would be high, but there's comparatively little training. Maintenance would be expensive, but rehab/repair decisions would be much less politically charged. Not sure how logistics costs would compare - "life-support" is probably lower, but sourcing power & spares might be greater.
I wonder if anyone has done an economic analysis on this sort of thing.
All of these deal with robotics and the military. Ethics is discussed widely, but visions and plans are also given (for which a cost analysis should be necessary, but I haven't found details).
Concluding, the current vision of the developed world's military seems to be to replace some humans with robots and have the rest work alongside them, giving them the most dangerous tasks. (A publication lamenting the fact that army operations can be life-threatening is somewhat ironic, by the way.) However, the previous points cited child soldiers, which are neither trained well nor do they receive the benefits you mention. So we're dealing with different contexts, and both statements make sense, IMHO.
Your hypothesis was that machines lower the entry level for war. The counterexample of using untrained, disposable child soldiers indicates that the entry level is already zero. Consequently, your hypothesis is wrong; the entry level for war is actually raised via expensive machines.
Central African Republic has war with child soldiers using machetes and guns. It's an unpleasant truth: humans are disposable.
This is evidenced by a bunch of stuff - rich westerners have their clothes made by poor people locked into unsafe Bangladeshi warehouses; have many of our goods made by low people in terrible and dangerous conditions; by our lack of interest in garbage pickers or street children or etc.