Donald Trump and the moon

Donald Trump signed Space Policy Directive 1 on December 11th 2017 and wants to put a man back to the moon again. And while the NASA's budget is at a all time low. But with companies which have or develop rockets in competition. From a financial view it should be feasible. But why is Donald Trump saying this now?

We've been at the moon, we've done this. Back in the 60s it was thrilling, winning the space race against the Russians. Which actually was part of the arms race. Other Presidents usually said Mars is the next target to go, like Obama. It seems like shortly after elected president most say something like that because they know the people like space. I don't know if this Space Policy Directive 1 is binding, or like with all the other US Presidents not much will happen.

May be one reason is to play North Korea, showing off with "We don't need to focus on a possible war with you and prepare. We have all out missiles already, can kick you ass any time. We are ready and until then we have time to waste some money for fun and put a man on the moon again, let's do some space exploration".