When the European Union was being advertised to European citizens, it was guaranteed that it was merely an economic agreement between the member states that would make travel and trading easier, and that's it. Each country would retain its independence and sovereignty. The fears that many had that the EU would become a nation all of its own, with each member state pretty much losing their independence and own government, is unfounded. Or so they said.
Some of the signs of a country's sovereignty are having its own currency, its own supreme government and justice system, its own constitution, and its own army.
The currency thing has long been gone, of course. The EU has become the top legislative entity controlling every member state, dictating the policies of all countries, and sanctioning countries that do not follow them. (With what authority? Who knows. But goes to show the what the status of sovereignty is). The EU tried to enact its own unified constitution for all member states, but at least that didn't fly (although, one could as if its replacement, the Treaty of Lisbon, is any better).
And, of course, for a long time the EU tried to create its own military.
Curiously, Britain was the strongest opponent to this idea, and it was essentially what held it back for over a decade. However, now that Britain is exiting the EU (at least allegedly), the EU has taken the opportunity and is now creating its own unified army.
If somebody still maintains the illusion that each member country could retain even their own military sovereignty, they are delusional. When the EU creates its own unified military, the top brass, the people at the very top, controlling all armies of all member states, will be assigned by the EU (probably unelected by the people). The EU will have control of all armies of all member states.
I still vividly remember all the talks by Finnish politicians about how EU membership would not mean the loss of any sovereignty, and that Finland would remain completely independent, and the government would stay in Finland.
Well, I suppose Finland will still have a government, for sure. It's just that it won't be fully sovereign. It will have to answer and obey the EU superstate.