When the Japan-U.S. security treaty was revised 60 years ago, nobody expected that it would become one of the most remarkable security alliances in history.

The treaty, which is the centerpiece of the two nations' alliance, has continuously provided a strong security architecture to protect the strategic interests — stability, peace and prosperity — of the two countries for more than half a century.

The alliance evolved organically over the years and adapted to the geopolitical challenges of the times thanks to the stewardship of alliance managers in both countries. What was largely an alliance designed to guard against communism during the Cold War has now evolved into a regional and global security infrastructure that covers new domains like cyber and space.