A military base deep inside Saudi Arabia appears to be testing and possibly manufacturing ballistic missiles, experts and satellite images suggest, evidence of the type of weapons programme it has long criticised its arch-rival Iran for possessing.

A pre-emptive, surgical strike against Kim Jong Un is risky, but his regime will soon have a nuclear-tipped intercontinental ballistic missile, say Isabel Reynolds and Enda Curran.

Tobin Harshaw talks to non-proliferation expert Jeffrey Lewis about North Korea’s nuclear programme and why the regime’s recent ICBM launch shouldn’t have come as a surprise