Estonia joined NATO in 2004. NATO Cooperative Cyber Defence Centre of Excellence was established in Tallinn in 2008. In response to Russian military operations in Ukraine, since 2017 NATO Enhanced Forward Presence battalion battle group has been based in Tapa Army Base. Also part of NATO Baltic Air Policing deployment has been based in Ämari Air Base since 2014. In European Union Estonia participates in Nordic Battlegroup and Permanent Structured Cooperation.