I think this war wouldn't had escalated to it's current state if Trump was the president then, he would done better than Biden in handling the whole situation amicably, Donald Trump is not an advocate of physical wars that results to the destruction of lives and properties and would rather priotise trade and economic war like the ongoing with China.
 So I don't think he would've even allow it start in the first place, talk more of allowing Ukraine join NATO which is on of the major cause of the war, the previous government have wasted billions in dollar just to fund Ukraine against Russia but that's something Trump’s wouldn't have tolerated.