President Trump’s confirmation that the United States may accept a presidential aircraft gifted from Qatar marked the latest escalation in his clash with Boeing.

The president might want to dump Air Force One for a luxury jet gifted by Qatar’s royal family.Boeing investors should take note.Today, two Boeing 747s—used interchangeably—become Air Force One when the president is onboard.

The Constitution bars federal officials from accepting gifts from foreign states without the consent of Congress.

The Qatari luxury jet offered to Trump is in San Antonio, Texas, suggesting that improvements to the plane may already be underway. But officials have raised security concerns.