Civil Aeronautics and Air Defence
Kudos to Propduffer for post on 20 May (20:18) - and not only because it bears repeating that indeed, the disappearance of a commercial airliner with all its passengers is an event of global interest and one in which many posters here hold unquestionably legitimate interests (despite some posters who may not).
On the subject of what actions the Malaysian military took, and what actions it failed to take: it appears reasonably clear that their inaction was far from optimum, and could have constituted a deviation from SOP....but this leads to a question. Is there part of any of the several ICAO Annexes which speaks to what steps a signatory nation's air defense authorities are "expected"* to take under circumstances involving loss of contact? ("Expected" because - as has been noted earlier on-thread, ICAO issues standards, not quite the same as "law".). Presumably the answer is a short and simple one, akin to "no of course not - no military is subject to the regulatory system for civil aviation; they'd never accept such a subordination."
But consider: let's just assume that having a single official holding charge over both civil aviation and a nation's military is a textbook exemplar of conflict of interest. Here, the informational deficits, and deteriorating official credibility, suffice to make the point (and for any doubters, the "shoot down" scenario is inherently intractable, isn't it?). So a reform could well be to require signatories to the ICAO regulatory architecture to separate the civil aviation authority from the country's national command authority. Where would this fit in the existing ICAO architecture? Or would it be an entirely new subject matter?