By building up its air defense forces, the alliance seeks to fill a key gap in its response to the threat of alleged "Russian aggression," the sources said, adding that this issue will be discussed at a meeting of NATO defense ministers in Brussels on Thursday.
Hit by economic malaise, economic crises and loss of export competitiveness stemming partly from the rejection of Russian energy resources, European allied majors including Britain and Germany have made cuts to social programs to fuel the military buildup.