In a move that blurs the line between commerce and geopolitics, the Trump administration is pursuing potash imports from Belarus — a country that opened its borders to Russian troops at the dawn of the Ukraine invasion. The proposal arrives as relations with Canada, long a reliable supplier of the same fertilizer ingredient, have grown strained under the weight of escalating tariff disputes. It is a moment that asks an old question in new terms: when a nation chooses its trading partners, is it merely buying a mineral, or is it casting a vote about the world it wishes to inhabit?