The U.S. Department of Defense has renamed the Pacific Command the U.S. Indo-Pacific Command. Adoption of this analytical framework aligns the United States with Japanese thinking, as Tokyo had first articulated the concept over a decade ago. Still, the intervening 10 years have not clarified the content of the "Indo-Pacific." It is incumbent on governments in Tokyo, Washington, Canberra and New Delhi to do just that if the concept is to have any real significance.

While the Indo-Pacific sounds new, it has a long provenance. The idea was first broached by Prime Minister Shinzo Abe in a 2007 speech to the Indian Parliament. It was adopted by the administration of U.S. President Barack Obama as it defined the geography of its "rebalance to Asia," and Australian diplomatic and defense officials have used it as their organizing framework since 2012.

The administration of U.S. President Donald Trump adopted the term in a speech last October by then-Secretary of State Rex Tillerson and it has since been used in key policy documents and by all U.S. officials when discussing the region. Adm. Harry Harris, head of the Pacific Command until last Wednesday, liked to say his area of responsibility stretched from "Bollywood to Hollywood, from polar bears to penguins." Renaming PACOM is merely catching up with that description.