Diversity jurisdiction doesn’t apply when a citizen of one foreign nation sues an alien from another country. But the presence of an alien on one side of a case between citizens of different U.S. states doesn’t destroy subject matter jurisdiction.The question for a federal judge in Massachusetts was “whether federal courts have diversity jurisdiction over cases between diverse U.S. citizens joined by alien parties on both sides of the controversy.” This was an issue of first impression in the 1st U.S. Circuit Court of …