The Ukraine Situation - sort of like Konfrontasi.

When Singapore, Sabah and Sarawak (and also Brunei, but they later withdrew) wanted to join the Federation of Malaya in the early 1960s, Indonesia was against the proposal. And when the Federation added these 3 states in 1963, Indonesia initiated Konfrontasi. 

Have you ever asked, "why Konfrontasi?" WTF does Singapore joining the Federation of Malaya got to do with Indonesia, right? 

Because Sukarno (then president of Indonesia) had a vision of a Greater Indonesia, one similar to the old empire (Majapahit, I think). Similarly, Putin has ambition (or vision, or delusion) of the old Soviet Union where Ukraine is "My Kraine".

So now Ukraine (like Singapore in early 1960s) wants to join NATO (analogous to Federation of Malaya), possibly eventually, joining the EU, but that's another story. Russia (analogous to Indonesia during Konfrontasi) wants Ukraine for herself, and objects. And the threatened invasion is similar to Konfrontasi, except Russia has quite a bit more capacity to prosecute a war than Indonesia in the 1960s. So if Russia objects militarily, it would be a lot more than a few saboteurs sent to Ukraine.