United States

Together, the carrier strike groups could generate “several hundred strike sorties a day for a few weeks, an intensity greater than during the 12-days war” said Matthew Savill, the director of military sciences at the Royal United Services Institute...“The question, however, is: what is all this buildup for?” Savill said. The sizeable deployment of air and sea assets suggests the US military is giving Trump the option of launching a wide-ranging bombing campaign, beyond an effort that might focus on Iran’s supreme leader, Ali Khamenei, and other senior figures.

Nuclear ambitions in China, Russia, North Korea and Iran – all states hostile to the West, with the first three located in relative proximity – may mean that the US seeks to divert resources to counter aggression, leaving Europe exposed. That “could create uncertainties over the ability of US strategic forces to simultaneously deter aggression in two theatres,” wrote Darya Dolzikova, a senior research fellow specialising in nuclear proliferation and deterrence at Rusi, a UK defence think tank, in a recent report. “Growing US requirements to deter both China and Russia raise concerns over just how much the US nuclear umbrella can stretch in terms of capabilities before it starts to leak.”

Keeping NATO partner countries on the sidelines of the summit “would send a signal that perhaps the focus is much more on core NATO issues,” said Oana Lungescu, a former NATO spokesperson and a senior fellow at London’s Royal United Services Institute.