Why Ukrainian plane tragedy unlikely to lead to global airspace rules

The wreckage of MH17. — AFP

MONTREAL/KUALA LUMPUR/PARIS: Why was the Ukrainian airliner mistakenly shot down near Tehran by Iranian forces last week for the loss of 176 lives even allowed to take off from a country that had just fired missiles towards its neighbour? And why didn't the airline just delay or cancel the flight?

In short - because a century of international air travel has yielded no international agreement on how or when to close airspace; and because airlines often have to rely on their own, sometimes incomplete, assessments to make the call for themselves.