it's my belief, and this is completely unfounded, that it's not Guliani whispering sweet "Ukraine!" in Trumps ear. It's Putin.
When Trump has private meetings with Putin, he asked Putin about the 2016 election interference. Putin denies very strongly. Trump presses - who was it then? Putin, knowing he needs an escapegoat, blames Ukraine - a country he is pressuring in every way possible to separate from the West - economically, politically, militarily. The best thing to do is drive a wedge between Ukraine and the US, and knowing Trump as a good KGB man does, he knows the 2016 election is the best way to do it. He sweetens the pot by having his computerguys go on 4-chan or whatever and make up anything they can to blame Ukraine, and they stumble on Crowdstrike.
Really, it's a brilliant play on Putins end and it has been wildly successful.
Mods> feel free to move to conspiracy theory thread if you feel it's more appropriate there.