Mike Baker

So the obvious question is, why would a relationship that important suddenly find itself at the center of a diplomatic dispute?

And the answer lies in one of the most painful and controversial chapters of World War II history.

In May, Zelensky issued a decree naming a Ukrainian Special Operations Forces unit after the Ukrainian Insurgent Army, better known as the UPA.

For many Ukrainians, the UPA is remembered as a nationalist movement that fought for Ukrainian independence against both Nazi Germany and the Soviet Union.

To its supporters, the organization represents resistance and the long struggle for an independent Ukrainian state.

But that is not how many Poles see it.

In Poland, the UPA is associated with the massacre of tens of thousands of Polish civilians during World War II.

The issue remains so sensitive that Poland's parliament formally recognized those killings as genocide back in 2016.

And that helps explain why Polish President Karol Nowrocki reacted so strongly.

In announcing his decision, Nowrocki argued that honoring the UPA was incompatible with holding Poland's highest state decoration.

He said the organization remains associated with, quote, "...cruel crimes against the citizens of the Polish Republic during World War II," end quote.

The decision was not lost on Kyiv.

In a social media post, Zelensky announced that he was returning the award, arguing that Ukrainians viewed the honor not simply as recognition of him, but of the sacrifices made by the Ukrainian people and military.

The post included images of the medal and what appeared to be a postal receipt, as if to make absolutely certain no one missed the fact that the honor was being sent back.

Kirill Budanov, one of Ukraine's most senior security officials, called Navrotsky's move, quote, an unfriendly act toward our people.

Four Ukrainian officials, including Budanov, announced that they would return Polish honors that they had received as well.

Now, before you assume that this means Poland is abandoning Ukraine, that is obviously not the case.

But it does raise the question, who actually benefits if this dispute continues?

Well, Polish Prime Minister Donald Tusk appears to have a clear answer.

Tusk, who's often taken a more conciliatory approach toward Kiev and is also a political rival of Navrotsky, urged both sides to lower the temperature.