The USA says its ‘strategic patience’ with North Korea is over, and suggests it might decide to take preemptive military action: the option was ‘on the table’ if the threat from North Korea’s weapons programme reached a level requiring it. The USA is now exploring a range of new diplomatic and economic measures, and continues to defend the deployment of its missile systems in South Korea. This angers China, but South Korea and the USA say the defence system is needed against North Korea's aggression (twenty years of persuading it to abandon its nuclear ambitions have failed). On Sunday North Korea had a powerful rocket engine test of ‘historic significance’, which could lead to the rebirth of the country's indigenous rocket industry. This came hours before US secretary of state Rex Tillerson met with President Xi Jinping of China - North Korea's only major global ally. Tillerson was thought to have raised the prospect of financial penalties on Chinese companies and banks that do business with North Korea. See