At the heart of tensions are eight uninhabited islands controlled by Japan that are close to important shipping lanes, rich fishing grounds and potential oil and gas reserves. China contests Japan's claims and is escalating its military activity in Japan airspace. In response, Japan has been doubling its F-15 jet intercepts.

The situation increases the risk of an accidental confrontation — and could draw other countries, like the United States, into a conflict. It's a topic President Trump will likely bring up with Chinese President Xi Jinping at his Mar-a-Lago estate this week.

From the departure lounge at Naha International Airport on the Japanese island of Okinawa, passengers can easily see what's going on. Between the regular comings and goings of commercial airliners, first one, then two, then two more F-15 fighter jets streak down the runway that Japanese Air Self Defense Forces (JASDF) share with Naha's regular airline traffic. Rising rapidly from the tarmac, the quartet of combat aircraft heads out to sea to intercept yet another Chinese military aircraft — usually other fighter jets, sometimes a bomber or reconnaissance plane — flying into or close to Japanese airspace.