President Donald Trump’s announcement that he was planning to seize control of the Gaza Strip and oust 2.2 million Palestinians, temporarily at least, has provoked shock and disbelief around the world.

The region has become a hot spot for the family’s business. Jared Kushner, the president’s son-in-law, noted last year that “Gaza’s waterfront property could be very valuable.”

Mr. Trump’s America First vision is a one-way street that erects walls to keep immigrants out but demands other territories give way to American security concerns, or development whims.