I think the problem with the idea of the EU as an international power is that they really don't have much of a common foreign policy and what common policies they have are also common with the US.
There aren't really any military threats to them either, Russia is weak and most EU nations are part of NATO(though the war is militarising Russia so they are probably more of a threat now than before) so their isn't much motivation for it. Really the EU is more of an economic entity than a geopolitical one and I think they are happy like that and that's for the best.