Federal law says a foreign gift worth more than roughly $480 must be accepted on behalf of the United States, not the person. The Constitution goes further: no gift from a foreign state at all without congressional consent. Congress has consented to none of these.
A samurai helmet from Japan's prime minister is diplomatic custom. Per an Axios review of State Department data, the Qatari aircraft is worth more than 100 times every other foreign gift accepted by a president since 2001 — combined. It is not the same category of thing.
Three features compound it. Taxpayers pay roughly another $400 million to convert it. Ownership transfers to the Trump Presidential Library Foundation by 1 January 2029, so a foreign state's gift ends up with an entity bearing his name rather than with the United States. And weeks before the arrangement surfaced, the Trump Organization announced a golf development in Qatar with Qatari Diar, the real estate arm of the same state's sovereign wealth fund.
The Justice Department reviewed it and concluded it violates neither federal bribery law nor the Emoluments Clause. That opinion is itself part of the record — it was produced by a department led by his former personal attorneys, and no independent ethics advisory opinion has been issued despite a formal congressional request.