4: DECAPITATION

This is probably the cheapest and least devastating option in terms of potential death toll.

The plan would require a highly covert operation in which special forces teams enter North Korea by air or sea and assassinate Kim and his inner circle.

The idea would be to force a regime change, putting a more moderate, West-friendly leader in power to open North Korea up to the rest of the world.

But as the CIA found with secretive regimes like that of Saddam Hussein, it can be difficult to plan an assassination without accurate intelligence.

Without knowing where Kim is going to be at a certain time, it is impossible to plan an attempt on his life. This kind of operation can also go horribly wrong, with troops taken prisoner and used as bargaining chips, as in the past.

But at the same time, special forces involvement is needed because sources on the ground would have to be checked – as would the intelligence. American special forces have almost certainly already operated in North Korea, helping the CIA recruit agents. There is no shortage of defectors willing to help gather intelligence on the Pyongyang regime. But North Korea is a difficult country to penetrate because all entry points are in problematic countries – China, South Korea and Russia. If the CIA could sign up a good source in the regime it would be able to pinpoint Kim. It is therefore possible he could be killed in a precision air strike.