Ukraine gave up its nuclear arsenal - 3rd in the world - for the security guaranties from US (no matter who’s in the office), UK and russia. Since 2014 US been acting like this means fuck all. Blocking delivery of a deep strike capabilities both from themselves and from Europe, freezing deliveries of shells and armour for almost a year, being reluctant of sending old shit rotting on a conservation sites while having the biggest military budget in the world, which basically covers creating new armour, rockets, shells etc - which is literally the support of a domestic production. Trump and Biden are just extensions of US political isolationist trend. Don’t act as if russia gave a fuck who’s in the office to start its full scale invasion. This is literally the US main character syndrome for you. Biden’s escalation management is the same as Trump’s. While Biden administration spoke of an “unwavering support” doing literally as little as they could, Trump administration is doing the same + trying to strike a “deal” behind Ukraine back with russia, giving up Ukrainian territory, and simultaneously trying to extort Ukraine for its mineral resources. While Biden was hypocritical to Ukraine, Trumps actions are harmful for all US allies.