TOKYO — Japan must strengthen its defense and seek a larger regional role as the balance of power shifts with the rise of China and the decline of American influence, according to a draft of a new national security strategy released Wednesday.

The draft, written by a group of experts appointed by Prime Minister Shinzo Abe, called for building even closer military ties with the United States, the postwar guarantor of Japanese security that still has 50,000 military personnel based in Japan. However, the paper also said that Japan must “strengthen its own capabilities and expand its own roles” by bolstering its antimissile defenses and its ability to defend the freedom of navigation in surrounding seas —apparently a reference to China’s growing naval presence in the region.

The new strategy did not call for a sudden buildup in forces, and it appeared to be consistent with the gradual increase in Japan’s willingness and ability to defend itself in recent years, especially since a dispute over islands has heated up with China. Still, it offered a glimpse of how far Japan has come from a firmly pacifist nation that just two decades ago was still reluctant to admit it had even a limited military.

Mr. Abe has vowed to give Japan an even stronger security posture, though he still emphasizes that Japan’s forces must remain purely defensive. Speaking to the group of experts, Mr. Abe called the draft a “historic document” because it is Japan’s first attempt at creating a national security strategy, and it comes as the country has created a new American-style national security council to strengthen its response to the changing regional environment.