In 2012, Barack Obama made an uncharacteristic gaffe that set off a small diplomatic crisis - he referred to the "Polish" - and not "Nazi" - death camps of the Second World War.
For Poles, it was an acutely painful faux-pas. The nation has for years objected to the term "Polish death camps", saying it implies complicity in the Nazi camps built on its soil during an occupation.
President Obama swiftly apologized, and a personal letter to Poland's then-president Bronislaw Komorowski was enough in that case to paper over the diplomatic crack.
But under a bill passed by Poland's lower house of parliament this week, someone using similar language in future might be prosecuted. Put forward by the ruling right-wing Law and Justice Party, the bill would make it a crime to accuse Poles of being complicit in the Holocaust, punishable by up to three years in prison.
President Andrzej Duda has indicated he will likely sign it into law. "There was no participation by Poland or the Polish people as a nation in the Holocaust," he said on Monday.
There is widespread agreement among historians that some Polish citizens did participate in the Holocaust, by betraying, even murdering Polish Jews. But there is disagreement over whether those acts add up to wider Polish complicity — a nuanced historical debate that the Polish government now seeks to legislate.
"This is history as a tool, as a means for a nationalistic government to accuse everyone else of betraying the nation while painting itself as the only true carriers of the Polish flag," said Anita Prazmowska, a professor of Polish history at the London School of Economics (LSE). "It is a blunt instrument."
It is also a product of the current political moment in Poland, where 60,000 nationalists took to the streets in November to denounce Islam and immigration, and where historians see a once progressive post-Soviet state taking a dark turn towards right-wing populism.