Ukraine President : pro - Russian rebels should be called terrorists . Richard Barrett : There 's no internationally agreed definition of terrorism . Under ' s definition , Malaysian plane 's downing would be illegal -- but only if intentional . Barrett : There are , however , many international conventions that define acts of terrorism , one of the earliest being the 1971 Convention for the Suppression of Unlawful Acts against the Safety of Civil Aviation , which would certainly cover the downing of the Malaysian airliner , so long as the act was shown to be intentional . The world is seeing a merging of terrorist states and quasi - states .
Ukraine President : pro - Russian rebels should be called terrorists . Richard Barrett : There 's no internationally agreed definition of terrorism . Under ' s definition , Malaysian plane 's downing would be illegal -- but only if intentional . Barrett : The world is seeing a merging of terrorist states and quasi - states .