It’s been one year since Russia invaded Ukraine.To mark the occasion, the president of the European Commission, Ursula von der Leyen, and the secretary general of NATO, Jens Stoltenberg, travelled to the Estonian capital. They also marked Estonia’s 105th anniversary of its independence from imperial Russia.After independence in 1918, the Republic of Estonia was absorbed by the Soviet Union until its collapse in 1991.So in the century since the founding of its republic, what has Estonia learned about Russia? And what has Europe learned since last year’s invasion of Ukraine?Estonia's prime minister, Kaja Kallas, talks with Al Jazeera.Subscribe to our channel http://bit.ly/AJSubscribeFollow us on Twitter https://twitter.com/AJEnglishFind us on Facebook https://www.facebook.com/aljazeeraCheck our website: http://www.aljazeera.com/Check out our Instagram page: https://www.instagram.com/aljazeeraenglish/@AljazeeraEnglish#Aljazeeraenglish#News