The EU has its own defense pact similar to NATO's Art.5, the Mutual Defense Clause. It was signed in 2009 (IIRC) to protect Greece from Turkish aggression, sinc

The EU has its own defense pact similar to NATO's Art.5, the Mutual Defense Clause. It was signed in 2009 (IIRC) to protect Greece from Turkish aggression, since Greece is in the EU, but Turkey is not. "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." Notice "by all the means in their power" which is different from Art.5. It basically means, that unless you're a officially a neutral nation, you are obliged to go to war.