The Japanese-U.S. security treaty in its current form turned 50 Tuesday. Throughout the decades, the two nations have had their ups and downs and occasional tension, but together they weathered the Cold War and entered a new era and new century.

Now, half a century after the bilateral pact was signed, leaders of the two nations have voiced an eagerness to strengthen the alliance.

But bilateral ties are strained at present, and how well Prime Minister Yukio Hatoyama and his Democratic Party of Japan-led ruling bloc can deepen them remains to be seen. Pundits say this is a good year to thoroughly review defense policies, and that a true deepening of the alliance to face the next 50 years depends on it.