Rosinate,
You are correct that military-level stealth is difficult to create. But I think you badly overestimate the capabilities of our current border protection schemes. Hot engine exhaust and the engine itself has to be looked for in order to be detected, how many National Guardsmen are currently staring skyward looking for engine exhaust with thermal imagers? Not many, I would wager. Back when we had the Nike-series of anti-aircraft missiles we might have actually had search-and-track radars operational at some points along the coast, but those have all been dismantled. Pretty much now, it’s skin-paint and transponder or get dismissed as noise until you’re so close it doesn’t matter.
There’s a huge difference between spoofing a civilian radar system and a modern military air-defense system. It’s doubtful anyone could get even a small plane through a Cold War-era anti-aircraft and anti-missile system and into a valuable target zone.
Oh, wait again. This guy was picked up by Reagan National Airport operators when he was 6.5 miles north of the White House.
