Faced with an increasingly severe security environment, Japan has embarked on a diplomatic push for closer defense ties with like-minded countries. And nowhere are the results of these efforts more evident than in this year's International Fleet Review.

Around 40 warships from 13 countries came together on Sunday in Sagami Bay, off Tokyo, to mark the 70th anniversary of the founding of the Maritime Self-Defense Force (MSDF).

Held to promote goodwill among the participating countries, experts see the MSDF-hosted naval parade as an exercise in Japanese defense diplomacy at a time of heightened geopolitical tensions in Asia and growing concerns about an increasingly assertive China and nuclear-armed North Korea.