Donald Trump's formal recognition of Jerusalem as the capital of Israel, reversing some seven decades of American policy, is arguably the most unnecessary decision of his time in office and one that will have consequences lingering far past his tenure. The decision may yield some domestic political advantage among Jewish and evangelical Christian voters for the president, but at irrationally high expense globally. Jerusalem is where Israel's president presides, and where the parliament, supreme court, and most government ministries are located. In practical terms, it is the capital. However, unlike in nearly every other nation, the United States maintains its...