FDR and Churchill both did the same sort of thing in office. They had held political appointments to positions as Secretary of the Navy and First Sea Lord respectively. Both meddled in naval construction to the cost and detriment of their navies.
With FDR, it would be the Alaska class large cruisers that the Navy didn't want, didn't need, but got anyway because they were a pet project of his.
With Churchill, one would be the 7" UP rocket projector his "Science Advisor" Frederick Lindermann was all in on. This POS weapon was near useless and possibly contributed to the sinking of HMS Hood.
My point here is, Trump is not unique by any stretch here. Politicians do this sort of stupidity all the time and it usually ends up badly. But don't make it out that Trump is somehow the first, or only, politician to do it. He's just the latest.