I don't see how Austria-Hungary could be seen as a proto EU, unless you mean that they couldn't agree on many things and had muddy compromises on authority and autonomy. How it could have created lasting peace is beyond me. Germany was its natural, but more powerful ally, and France, England and Russia were sworn enemies of Germany, and didn't seem to care for the double monarchy. It had very little credit in world affairs, so how could it have swayed the whole continent?
Also: we're not on the cusp of WW3.