Pakistan, Nov. 4 -- On the very day Americans went to the polls to decide who would control Congress, President Donald Trump produced another of his trademark surprises. Washington, he announced, would stop providing Israel with roughly $4 billion in annual aid after 2026, following an understanding with Prime Minister Benjamin Netanyahu. The announcement came with a political explanation. Financial assistance to Israel had become a convenient stick for his opponents to beat Republicans with. Trump appeared determined to take that stick away.

With control of both chambers hanging in the balance, the president seems to have waded into one of Washington's most contentious foreign-policy arguments. Yet the headline also captured the peculia...