This week, the defense ministers of China and Japan held a 20-minute-long phone call. The content of the call itself was unremarkable as one might expect from such a short conversation.

But the call itself was epoch-making for Northeast Asian security because it happened across the two countries’ newly established defense hotline. All told, this brief call was 15 years in the making.

Some might be wondering whether this is actually a big deal. In today’s world of email, smartphones, videoconferencing and instant messaging, why is a hotline significant? What can it really do to manage conflict between these two powerhouse nations?