On a Chinese hospital ship off Hawaii, crew members demonstrate traditional massage techniques to U.S. sailors. The mood is one of collegiality, even after China opted out of Japan-led humanitarian drills at the world's largest international naval exercise.

There are no guns in sight as Senior Capt. Sun Tao stands on the deck of the Peace Ark, which is taking part in the five- week-long Rim of the Pacific Exercise, known as RIMPAC. Inside the ship, sailors tuck into fatty pork and steamed buns, watching President Xi Jinping on state television, while others give out Chinese massages.

"The Chinese navy now is acting on orders to have a cooperative and open attitude," Sun said after Chinese navy cameramen filmed reporters visiting its eight operating theaters, dental facilities and CT scanner. "I think cooperative areas are growing wider."