Defense Secretary Robert M. Gates, center, Japan's Minister of Defense Toshimi Kitazawa, right, and South Korean Defense Minister Kim Tae Young, shake hands during the Shangri-La Dialogue's Asia Security Summit in Singapore, Saturday, June 5, 2010.

Defense Secretary Robert M. Gates, left, shakes hands Japan's Minister of Defense, Toshimi Kitazawa, during the Shangri-La Dialogue's Asia Security Summit in Singapore, Saturday, June 5, 2010.

The Chinese military's deputy chief of staff, General Ma Xiaotian, listens as Defense Secretary Robert M. Gates delivers remarks during the first plenary session at the Shangri-La Dialogue's Asia Security Summit in Singapore, Saturday, June 5, 2010.
U.S. Defense Secretary Robert Gates challenged China to deal realistically with the short-term question of how to respond to an antagonistic North Korea and the longer-term issue of whether Beijing's expanding military can establish more durable ties with the U.S.
Asian nations cannot stand by in the face of North Korea's alleged sinking of a South Korean warship, Gates said during an international security summit Saturday that was dominated by questions about the North.
"To do nothing would set the wrong precedent," Gates said.