(1) The CIA World Factbook was often a nice source because it's not suspected of being biased against the U.S.. Whoever runs this thing in the agency did decide to remove the information on military age males. There's some info on age groups, but categories like "15-24 years" and "25-54 years" are not helpful when the topic is demographics and military personnel potential. Nor does the factbook feature figures about the quantity of reservists.
(2) Stored Russian tanks. The IISS and some other sources publish figure about what quantity of tanks of what types Russia has in storage, but there's very little indicator of quality other than types. I'd like to know how many are really in storage (not sold on black markets long ago already) and in what conditions. I strongly suspect that the Russians did not put many tanks in storage without cannibalising them for spare parts, and mere steel shells with worn-out gun barrels, worn-out tracks about to break, engines in need of overhaul and hardly any electrical equipment would constitute a very different material reserve than tanks in operational condition.
(3) Quantity of modern Russian air combat missiles. Rumours are that they purchased only pitiful quantities of modern air combat missiles post-1992 and are largely stuck with 1980's missiles that are way beyond their shelf life.
(4) Russian brigades involved in the aggression against the Ukraine. As far as I know most Western Military District and all Southern military district army brigades have detached each one battalion battlegroup for combat in or threatening the Ukraine. They rotate personnel between the brigades and their detachments. My question is did they cannibalise the brigades or are the left-behind elements of the brigade in fully operational condition?
(5) Info on military and paramilitary spending in purchasing power parity. I think this was in the CIA world factbook at some time as well.
I can look up the military spending in IISS "The Military Balance 2016" (European NATO spending 5x as much as Russia), but only so in currency exchange rates (and event hat's a bit tricky because the exchange rates aren't stable). Some hidden military expenses aren't necessarily included there either.
I would like to have stats on PPP military spending in Europe and Russia. The fivefold relationship won't be turned around into Europe spending less in PPP; but we lack accurate, quotable figures.
(6) Overview over Russian and Chinese naval shipbuilding plans (not really relevant for Europe, just curious)
(7) Overview over Western naval shipbuilding plans (not really relevant for Europe, just curious)
(8) Availability of night vision devices in Western and Southern Military District ground forces of Russia, and in VDV.
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Should be easy:
Not easy, but should be known anyway:
May require good insider sources:
Intelligence services are often thought of as providing information to the top of the government. I suppose in democracies they should provide much of their information to the sovereign - the people - as well. Few do so (the CIA World Factbook is a small, laudable effort), and I think they owe the people for all those public funds (previously taxpayer money) they get.