a combination of personnel and technology, ie. scanners x-rays, drones etc.,for security.
Sadly we never even stop in Tijuana anymore since the time they had tanks and armed military on the main roundabouts.
Due to age we usually skip Rosarita too on the way to
https://www.golfbajamar.com/
We still enjoy dinner in the nearby fishing village of Puerto Nuevo.
Trump cited an area crime and described it as California rather than mentioning San Diego specifically..