The US has delayed shipments of Tomahawk missiles to Japan due to its focus on the Iran-Israel conflict, which is affecting supplies and troops against China and other strategic rivals.

Japan’s order for hundreds of Tomahawk missiles from the US is under threat as the American-Israeli war with Iran burns through inventories, the latest example of how the conflict is drawing in supplies and troops at the expense of defending against Washington’s primary strategic rival, China. Tomahawk missiles are a centrepiece of Tokyo’s new strategy of equipping itself with long-range strike capabilities to deal with challenges from China and North Korea. But Washington has informed Tokyo...