Everything he does results in failed relationships.
But in politics, failed relationships means nothing happens. Including administering government. Including walls.
His supporters will say it's the art of the deal. He gets leverage by being unreasonable. But he doesn't get anything useful from his strategy. At best, he gets something to save his face because folks on the other side see he offers them nothing. So, like with NAFTA, they stick a new name on a treaty and pretend it's a victory.
Nothing he is doing is working. He has damaged any corporation reliant on trade. He has damaged NATO and the wars the US is conducting. He has damaged the environment. He has damaged the US government. He has damaged the friendships the US had since WW2.
And what do Trump's supporters get?
Tax cuts for the wealthy. Otherwise, nothing.
They are rubes all the way down.