Russia is not an aggressor in case of Crimea, because 96 percent of Crimeans voted for joining Russia.
The only thing which keeps the members of NATO united is “Russophobia” and hostility towards Russia.
Recurring pro-Kremlin disinformation narrative about Russophobia. It groundlessly alleges that NATO countries are kept together only thanks to consolidation around their anti-Russian positions.
NATO was founded in 1949 by twelve sovereign nations: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom and the United States. It has since grown to 29 Allies who each took an individual and sovereign decision to join this Alliance. After the end of the Cold War until the 2014 Ukraine crisis, most US and Western policymakers no longer viewed Russia as an adversary, instead, taking the opinion that it could potentially become, or already was, a credible and responsible partner for Western states.
Read earlier disinformation cases alleging that the US and EU countries are Russophobic, that anti-Russian position helped NATO countries freeze a drift in different directions and that Russian threat is an invention.
For background, see EUvsDisinfo analysis "The “Russophobia” Myth: Appealing to the Lowest Feelings" here.