Poland finds itself in a bind. For the past two years, Warsaw has lobbied Washington for an increase in American troop presence on its territory. It now appears likely that it will get at least some of what it wants, but that could be at the expense of America’s presence in Germany. Should that happen, Warsaw would find itself at odds with its economically powerful neighbor, a circumstance that — given the tragic history of German-Polish relations — the Polish government wishes to avoid. Not surprisingly, Polish Prime Minister Mateusz Morawiecki made clear, “It is not [Poland’s] intention to achieve...