US Air Force B-1B bombers (centre), F-22 fighter jets and South Korean Air Force F-35 fighter jets (bottom) fly over South Korea during a joint air drill on January 1. On February 2, North Korea threatened the “toughest reaction” to the US’ expanding joint military exercises with South Korea to counter the North’s growing nuclear weapons ambitions, claiming that the allies were pushing tensions to an “extreme red line”. Photo: South Korean Defence Ministry via AP