Mosbacher, a businesswoman nominated by President Donald Trump, attributed the rise of anti-Semitism in Eastern Europe to a law passed in Poland in January that criminalizes blaming Poland for Holocaust crimes committed by occupying Nazi Germany. The law drew angry reactions from Israel, which in turn triggered a wave of anti-Semitic rhetoric in Poland.
https://www.seattletimes.com/nation-world/us-envoy-nominee-ok-for-poland-despite-polemic-words/
Many on the right objected to her characterization of the law and its consequences, and to things she said that flouted the law--which was simply that the Polish government had not participated (leaving open whether individuals, several or many, had participated). It's a touchy subject for obvious reasons, not the least of which is that Poland's been snubbed repeatedly after being betrayed by some of the Allies prior to WWII even after having suffered arguably the most (Belorus and Ukraine are high on the list and may be #1 & 2) under the Nazis and still having had the strongest partisan-resistance movement. Even fielding over a dozen RAF squadrons. (Meanwhile, France's resistance, smaller, is lionized, and its WWII occupation government, collaborationist to the core, pretty much given a pass.) I mean, as far as it goes, there's a point there; but part of the point tries to deny guilt for what many Poles did do.
It also doesn't help that not all Poles collaborated with the Nazis, and that Poles were also both the subject of Ukrainian nationalist pogroms (but we only remember the Jewish victims) and The post-WWII history doesn't help, either, acquiescing to Poland being a Russian satrapy. Neither did pre-WWII history: Few knew of Katyn, and fewer yet of the Polish-Soviet war. Lenin rather though the Bolshevik state deserved to be an empire. (So much for the USSR having "anti-imperialist" roots.)
3 million Polish Jews killed. A bit under 2 million Polish
civilians killed by the Germans. Over a million deported to work camps in Germany. Hundreds of thousands ethnically cleansed from western areas to import German settlers, with 10s of thousands of Polish kids taken to be "Germanized" and raised as German. Then after the war the US agreed with Stalin to shift Poland's borders, ethnically cleansing a 100-mile deep zone on the east and giving the Poles German territory on the West--undoing the result of the Polish-Soviet war and pleasing our esteemed and admired ally, Stalin, to no end. Of course, they immediately ethnically cleansed the Germans, just as they'd been ethnically cleansed by Germans and by the USSR with American and British consent, but have gotten grief for that ever since. Most often by the US and by, of all groups, the Germans.
Not all victims are purely innocent; not all oppressors are purely evil. Many thought Mosbacher, a Trump appointee, was a good choice to bring enlightenment to the Poles. She's still a bit of a lightening rod for the opposition. She tweets "It's a nice day" and one of them will take offense.