What I base my opinion on is the following.

a.) Since 1945, we (UK/US) are usually wrong about where and against whom we will be fighting. This is not likely to improve. Why do we keep trying?

b.) Since about 1973, we have seen very little, if any, in the way of "technical surprise" in the conduct of warfare. Almost every weapon encountered is very well known.
  • Every weapon Hezbollah used in 2006, was well known to IDF intelligence.
  • The Taliban are using 40 year old weapons, within an entirely predictable tactical doctrine.

Yes there are emerging technologies, but they usually don't have a proven and coherent military application, so are not really much of a threat.
If you have some understanding of potential technical capability then how that capability is used, is usually mind-numbingly obvious.