Why are Europeans worried about Russian aggressiveness?
Because Europeans worry about being targets of Russian aggression. Duh.
Although to be fair, perhaps CNN's usual audience needs this reminder. The article actually does take a nice tour of European countries fearful of Russian aggression.
Although I dispute the argument that part of the worry in Europe stems from Donald Trump's "public admiration" for Russia's Putin. Well, it might stem from Trump if the Europeans believe reporting like that.
My take is that rather than admiring Putin and his policies, Trump admires Putin's willingness to project an image of strength to pursue Russian interests. That's more of a contrast to President Obama than a love note to Herr Putin.
And perhaps I missed the Obama administration's repudiation of the "reset" initiative under Secretary of State Clinton.
As for Trump's statements about potentially not defending NATO allies who don't pay enough for defense?
Well, I strongly defend the value of NATO so do not want this to be our policy. But we have long cajoled NATO allies to spend more money on defense. We had little effect until Russia started acting all Russia-like, but progress is slow and uneven. The new statements by Trump may just be a more forceful effort to get these allies to spend more.
And in some sense, the threat by Trump is merely a statement of fact. If Russia can quickly overrun a NATO ally because it is so weak, how can NATO mobilize to defend the ally, regardless of what we are willing to do?
Stronger NATO frontline allies can resist longer and compel Russia to visibly mobilize forces prior to an invasion. Both factors buy time for NATO to mobilize and react to deter a Russian attack; and if Russia attacks anyway, to contain the Russian attack before they reach the Suwalki Gap and prepare to counter-attack into the Baltic states and to conquer Russia's Kaliningrad exclave.
As long as Trump's rhetoric doesn't encourage Russia to think America won't resist their aggression and that they could get away with a land grab against a NATO state in an effort to demonstrate NATO's inability to resist Russia, there is value in alarming low-spending allies.
But it is nice to see CNN admitting that European states have reason to fear Russian intentions. I welcome the "reality-based" community to the ranks. Given the evolution in thinking of CNN's audience, this was inevitable.