When China commissioned a refurbished Soviet aircraft carrier into its navy last September, the appearance of the 67,000-ton Liaoning made headlines around the world.

It’s not considered much of a threat to the US Navy. The quarter-century-old ship is barely half the size of the latest American super carriers.

But it did mark China’s expansion into naval aviation’s offensive realm. Added to its assertive demands for sovereignty over vast areas and islets off its coastline, this has many worried that a potentially dangerous naval arms race has taken hold in Asia.

Japan now has responded with the inevitable: Izumo, the largest warship the Japanese navy has built since World War II.

Japan has forsworn offensive weaponry since the war.