CAMP HIGASHI-CHITOSE, Japan-On the eve of the 50th anniversary of the U.S.-Japan mutual defense treaty, U.S. and Japanese forces have successfully concluded a major exercise here on Hokkaido, the northernmost island of Japan. Yama Sakura, an annual joint and combined full-spectrum training exercise, this year involved 1,500 U.S. service members and 3,500 members of the Japan Ground Self-Defense Force. Its focus was the refinement of bilateral planning, coordination, and interoperability. "This exercise proves the strength of the long-standing relationship between the U.S.