A lot of Europeans have asked if I would do a comic about how some Americans act like they personally ended WWII, and the irony of "Do you speak German? No? You're welcome!" of course being that a lot of countries outside of Germany are taught German in school. Not because of WWII, but because Germany is a big and important country so it helps to understand the language. Even I who can only speak very little German understand quite a bit of it, and I don't even know why.
Next after Sweden and Norway, Germany is Denmark's best friend, especially in the tourist season. They have always had a bit of a "I hate to love you" relationship ranging from Denmark still imitating Germany when they were at war, to Germany still wanting to go to Denmark even after it felt betrayed when Denmark briefly got it's border control back.
Even during WWII Nazi Germany treated Denmark nicely (Well, as nicely as Nazi Germany could treat anyone) and made it possible for Denmark to ship 99% of it's Jews to Sweden before Denmark got invaded and then made an agreement with Nazi Germany that the remaining Danish Jews weren't allowed to get killed and not be sent to the really bad concentration camps. Danish Jews became quite popular in the camps they went to because the guards would usually steal the food that was sent to people in the camps, but only stole cigarettes and candy from the Danish Jews thanks to the agreement, so they had something to share with people.
And that is the long answer as to why Denmark don't want America to beat Germany up. The short answer being "because he wants Germany to visit his beaches"