Hijacking
Hijacking is a problem of recent origin faced by the airlines anyone who has a personal grievance against a government finds it convenient to hijack a plane to attract worldwide attention.
The first recorded aircraft hijacking took place in 1931.When the aircraft was ceased after it landed in an aerodrome in Peru by armed rebels after an unsuccessful attempt to throw the Lima government and demanded to flown to Chile.
Hijacking became a major problem in mid 60's. When the terrorists group used it as a weapon for international blackmailing.The International community forced ICAO to take appropriate action. So ICAO imposed penalties for offences committed onboard of an aircraft and powers of the commander of the contracting states
ICJ - International Court Of Justice.
In some countries they do keep sky marshals or air marshal in mufti dress with concealed weapons onboard of the aircraft.
In the Tokyo convention in 1963 in Japan, the convention provided the contracting states in which the hijacked aircraft lands shall ensure restoration of the control of the aircraft to lawful commander and allow the passengers and cargo including aircraft to proceed to their known destination as soon as possible.
Air force Commandos - Garud
Marine Commandos - MARCOS