Earlier this month, I travelled to Tokyo, where I caught up with some Japanese friends. As we chatted about global affairs, one of them, Michiyo, revealed that her doctor husband had recently given her anti-radiation pills to carry in her handbag.

The reason? Not the leak of radioactive material that occurred at the Fukushima nuclear plant after it was hit by a tsunami six years ago. Instead, what worries Michiyo’s husband is North Korea.

In recent months, the secretive country has conducted an escalating series of missile tests, including one just last week. This has sparked fears among western intelligence services that Pyongyang could be close to acquiring an inter-continental ballistic missile with the ability to deliver nuclear warheads to places such as Japan, Guam, Hawaii or even California.