Trump can make a deal. That doesn’t mean it’s a good deal. A good deal for him personally may not be a good deal for the US.
There’s the famous story of when Bill Gates dealt with the IBM lawyers as young nerd, and used the image of suits= knowledge + power, nerd with T-shirt = clueless + easy to manipulate deliberatly to get himself a good deal because the lawyers didn’t understand the implications of software.
So … maybe Trump is just pretending to be abysmally stupid in order to trick everybody, and will make awesome deals.
or… by pretending to be dumb, he has turned dumb (because that happens mostly in the real world.
There’s another aspect: Besides things like reneging on promises, that is, cheating his employees on their wages, there are stories like his Flag-pole building trial, where he deliberatly broke the law with a small city, knowing that a small city couldn’t afford thousands of lawyer hours, and reached an agreement for the much larger violation. So he’s gotten used to either making deals with other rich guys where favours are traded (and not realizing if he got ripped off), or squashing people he’s ripped off with his hordes of lawyers.
That doesn’t work on the international stage.
I wonder where the illusion about Germany comes from. UK, yes, they are Brexiting. France, might be with Le Pen having about 40 %. Austria made some noises right after Brexit, and was then ignored again by everybody. Wilders for NL was just struck down.
But despite grumbling, nobody in Germany really wants to leave the EU. Pegida makes headlines, but is not a party, and the AfD is fracturing, and talking more about the Euro, than a total Exit. The biggest embarrassment in that regard is (once again of course) Seehofer, cozying up to Orban and Putin and talking about Bavaria making seperate trades with Russia despite sanctions. But only people who aren’t savy would take Seehofer seriously.
The press commented that while Merkel wanted to get closer to Trump for the sake of German industry, she had to walk a fine line because of the “distaste” for Trump in German - any kowtowing would damage her, and we have an election this September. (Not that it will change much - all current predictions point to both major parties at 30%, the rest too small, so Great coalition likely continues.)