Spain and Belgium have taken over NATO’s Baltic Air Policing mission
The two countries replace Hungary and Germany in the role. 
Spain will lead the mission for the first four months of 2016 with four Eurofighter Typhoon jets based in Lithuania. Four Belgian F-16 fighter jets will be based in Estonia.
The mission to protect the Baltic skies was set up in 2004, when Estonia, Latvia and Lithuania joined the alliance, to support countries that don’t have their own fighter aircraft. 
NATO allies protect their airspace on a 24/7 basis, with efforts focused on stopping incursions into NATO airspace.