A newsletter circulated after the Islamic State's November massacre in Paris, shows the objectives of Daesh, which is to break the EU unity and weaken economically the European states.
From the TheIntercept :
A newsletter circulated after the Islamic State’s November massacre in Paris sheds light on what the group believes yesterday’s [22/3] deadly attacks in Brussels will accomplish, including weakening unity on the continent and exhausting European states economically.
An issue of the Islamic State newsletter al Naba, published weeks after the Paris attacks, boasted in one section that “the Paris raid has caused the creation of a state of instability in European countries which will have long-term effects.” It listed these as “the weakening of European cohesion, including demands to repeal the Schengen Agreement … which permits free traveling in Europe without checkpoints”; “security measures [that] will cost them tens of millions of dollars”; and “mutual accusations between France and Belgium” over security failings.
Well, the EU is dissolved by itself from the inside. It is not the terrorist attacks that are doing the job, but the failed policies followed by the political puppets of the bankers and the lobbyists. EU failed to deal effectively with the economic crisis and lately, with the refugee problem. The IMF-type catastrophic policies have already destroyed the economies in the periphery, especially Greece. These policies are now spreading to the heart of Europe, for example, France.
The extreme nationalist parties gained significant power long before the terrorist attacks, mainly as a consequence of the economic crisis and the high unemployment.
Despite the course of spiral death, the Brussels-Berlin axis insists, even now, in the catastrophic policies that lead the economies to a slow death and feed further the extreme nationalism.
Therefore, Europe doesn't need any terrorists or any other "help" to be dissolved. It can do it by itself and indeed doing a fine job until now.