(CNN) -- At sea, on land and in the air, Russia has been flexing its military might this year in a way that hasn't been seen in a generation. NATO has scrambled jets more than 100 times to intercept Russian aircraft near European airspace in 2014 -- three times as often as in 2013 or 2012, the alliance says. Sweden launched a huge naval operation in search of a mystery submarine in October, an Estonian security service operative was abducted in September, and Russian aircraft buzzed American and Canadian ships in the spring and summer.
The incidents are outlined in "Dangerous Brinkmanship", a European Leadership Network report which describes three of the incidents as "high risk" and calls 11 others "serious."
Here are the most alarming incidents and NATO's response.
Source: European Leadership Network