This isn't just Trump talking.
Trump has already survived three documented assassination attempts. Federal prosecutors have also convicted an Iranian IRGC operative in a murder-for-hire plot that DOJ says included plans to assassinate Trump. And U.S. officials have received additional warnings concerning Iranian threats against him and his family.
Meanwhile, the U.S. military and DHS have been treating drones, including increasingly autonomous systems, as a serious homeland-security threat.
So put the pieces together: a President who has already been shot at, another would-be assassin positioned with a rifle near his golf course, documented Iranian assassination plotting, and rapidly advancing autonomous-drone technology.
The location itself makes strategic sense. The proposed arch would sit at Memorial Circle, at the Virginia end of Arlington Memorial Bridge, giving an elevated position with unusually open sight lines over the Potomac and the western approach to the Lincoln Memorial, National Mall, and central Washington.
For counter-drone surveillance, detection and interception, that geography is hardly arbitrary.
The need to harden the White House and Washington against drone and sniper attacks is not imaginary. The threat environment is real.

@RobertWMalone