Russia conducted its operations between both Trump administrations… Trump has nothing to do with the likes of Russia and China aggressively undermining the international law and the ‘rule based order’.
Even during the Obama administration, the US was criticised for drone strike operations and the Bin Laden assassination also criticised for violating international law.
This ‘rule based order’ was always a construction and could only be sustained if the US was a sole hegemon. Even Russia protested furiously at NATO intervention in Yugoslavia and the recognition of Kosovo. In practice, because the UN Security Council comprises the UK, France, USA, China and Russia… there will rarely ever be a “legal” war because all 5 permanent members can exercise a veto. Lo and behold, it’s Russia and the US who have vetoed the most resolutions.
Major powers will almost always act in the own self-serving interests.