Neutrality means that a country does not take sides in a military conflict and refuses to become a member of a military alliance.
Among the 28 EU member states, Ireland, Sweden, Finland, Austria, Cyprus and Malta are neutral. They are not members of any military alliance and are not bound by a mutual defence commitment in NATO.
The Lisbon Treaty calls upon all member states to support the CFSP. Neutrality is not mentioned in the Lisbon Treaty, yet the "specific character" of member states' foreign policies is referred to.
Under the treaties, the neutrals will be allowed to take part in military EU operations if they wish, but they are not legally obliged to. They will not receive or share NATO military secrets, as the EU members that participate in such operations do.
Finland has formally changed its policy of staying free of alliances to adopt the EU treaties.
Sweden and Ireland have decided they do not want to take part in wars or military activities without approval from the United Nations. The Lisbon Treaty does not require a UN mandate for EU participation in wars.
Article 42.7 TEU contains what some regard as an EU mutual defence clause.
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See also Defence.