The OSCE (Vienna-based) noted that Ukraine had 60,000+ troops massed on the border with the Donbas, and had increased shelling by 3x in the weeks prior to Russia's invasion. Russia used the UN charter Chapter VII article 51 to invade, saying their invasion was to stop an even greater humanitarian crisis. I do not have the legal expertise to judge that justification.

Because of #Russiagate, Trump was more hawkish in policy than Obama. Trump's rhetoric was something else, but Trump was against Nordstream II and sanctions companies working on it. Trump sent advanced weapons to Ukraine that Obama would not. Trump took the US out of the INF treaty with Russia.

Trump in reality was no ally to Putin and made the world much less safe. But that reality did not fit with the fantasy that Trump being a secret agent of Putin.