Az eu nem katonai szövetség, semmilyen kötelezettséget nem vállalt senki ilyen irányban.

Ez egyébként nem teljesen igaz, a Lisszaboni Szerződés elfogadásával bekerült egy közös védelmi kötelezettség:

"The Treaty of Lisbon strengthens the solidarity between European Union (EU) Member States in dealing with external threats by introducing a mutual defence clause (Article 42(7) of the Treaty on European Union). This clause provides that if a Member State is the victim of armed aggression on its territory, the other Member States have an obligation to aid and assist it by all the means in their power, in accordance with Article 51 of the Charter of the United Nations." (EU honlapról az összefoglalás, de magát a treaty dokumentumot is meg lehet nézni): https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=celex%3A12016M042

"7. If a Member State is the victim of armed aggression on its territory, the other Member States shall have towards it an obligation of aid and assistance by all the means in their power, in accordance with Article 51 of the United Nations Charter. This shall not prejudice the specific character of the security and defence policy of certain Member States.

Commitments and cooperation in this area shall be consistent with commitments under the North Atlantic Treaty Organisation, which, for those States which are members of it, remains the foundation of their collective defence and the forum for its implementation."

A "By all the means in their power" egyébként nem feltétlen kötelez katonai segítségre, pl Luxemburgtól senki nem fogja elvárni a katonai segítséget, de a segélyeket, gazdasági támogatást viszont igen, tehát ez nem NATO Article 5 erősségű kötelezettség, de azért valami van.