re: Reasonable questions
I would think our immediate military concerns in space are with our military satellites. Our GPS, weather and imaging satellites could be vulnerable to nanosatellites or parasitic satellites that can send microsatellites that stick to our satellites and are undetectable until activated.
If we ever find ourselves in a military situation with China and Twain for instance the Chinese could activate these parasites on our GPS satellites and could obstruct our smart bomb capabilities. The same goes for our spy satellites and so on as in our computers and information infrastructure required to make military decisions.
Although I'm sure or military has deployed counter missions to offset these nanosatellites it has to be of great concern.
SteveS