We need to put undercover security armed people at the curbside of the terminal with the uniform of policemen. We need to protect the terminal. We need to protect the security checkpoint, the gate, the aircraft, the perimeter.
There is only so much negotiating and maneuvering that can be done while the aircraft is under siege in mid-air. Therefore, the best way to put a stop to hijacking is by having high levels of security implemented by qualified and trained personnel both on the ground and in the air.