The chairman of the U.S. Joint Chiefs of Staff has warned that the danger of war on the Korean Peninsula is rising.

Admiral Mike Mullen told troops in Baghdad on Monday that North Korea has upped the ante in its aggression against South Korea. He said such a pattern is related to preparations for North Korean leader Kim Jong-il to hand over power to his son. He added that only China has the power to rein in North Korea and that China should use that power.

Former U.S. Defense Secretary William Cohen said he believes North Korean threats of nuclear war must be taken seriously, adding that being prepared is the best way to deter any conflict.

Cohen said he believes the U.S. must increase its military presence in the Northeast Asian region on a contingent basis.

He said that China should withdraw support until the North Koreans see that they will no longer be able to rely on the Chinese. He said that such a move could be the only way to bring the North to the table to talk about peace in a meaningful way.