Sarajevo involved the assassination of the Austrian Crown Prince and his wife. The equivalent would be the assassination of the leader of a major NATO power by a Russian ally. Not the same thing at all. The Russians will always have a reason for territorial expansion - that's what Russians do.
Frankly, it doesn't appear NATO is prepared to lift a finger in response, so the appropriate analogy isn't Sarajevo 1914 - it's Budapest 1956. Except this time, while NATO won't send troops, it will send weaponry. And Ukraine will either rerun the Ukrainian Insurgent Army's losing campaign in the 40's and 50's or the Afghan insurgency's victorious war in the 80's. Either way, Ukrainians will pay a heavy price and Russian military suppliers will do a brisk trade in body bags.
I agree with you. I was just making an easy analogy due to the centenary.
I work with some Ukrainians. Both are very pro western and pro Nato, but I also know Russians and Serbians and other East Europeans...
There is a lot of hatred. I do t think a shooting war could happen again. Well outside of Ukraine where it already is.
What effect Nato has in it, is up in the air...