Short of a catastrophic event that would force the EU to band together to fight a ridiculously large, ridiculously powerful enemy, I just can't see this happening.
The economic state of many European countries right now already limits what they could spend on their military. They've been so used to a general US military hegemony that they could skimp as necessary, and I don't see them likely to find the need to suddenly invest the time, energy, and financial resources into implementing one united military. Think about all that would go into it. Agreement on tactics. Agreement on command structure. Uniform pay for soldiers. Uniform equipment. Uniform...uniforms. The training to get everyone on the same standard. Cultural differences.
It's a lot to surmount. It's not impossible, but it's unlikely to happen without the EU being forced into it.
The economic state of many European countries right now already limits what they could spend on their military. They've been so used to a general US military hegemony that they could skimp as necessary, and I don't see them likely to find the need to suddenly invest the time, energy, and financial resources into implementing one united military. Think about all that would go into it. Agreement on tactics. Agreement on command structure. Uniform pay for soldiers. Uniform equipment. Uniform...uniforms. The training to get everyone on the same standard. Cultural differences.
It's a lot to surmount. It's not impossible, but it's unlikely to happen without the EU being forced into it.