Everything that Migeru outlined is true.

If I may however clarify re European Battlegroups (BGs): apart from the fact that a political decision was arrived at, i.e., to prevent duplicating NATO efforts, a recent report commissionned by the European Parliament asserts that a majority of the BGs are ill-equipped and ill-prepared to take on the wide range of missions for which they are
intended. This is the main reason why I think that for the time being Europe has no credible BGs along the lines of a simile NATO.

Anyway, it is unlikely that we will be having full-scale European Defence BGs for the reason Migeru advanced above -- just too much on the budget front for member nations.

All in all, must say I absolutely agree with Migeru: "It is not NATO that hinders the ability of Europeans to act indepedently, but the political determination of Europeans not to act independently."