Washington (CNN) -- Monday's rare meeting at the State Department between Secretary of State Hillary Clinton and the foreign ministers of South Korea and Japan had a three-part aim.
At the very heart, the talks were designed to shore up the alliance of the United States, South Korea and Japan, which is governed by a mutual defense treaty. When Clinton warns North Korea's behavior threatens all three allies and "will be met with solidarity from all three countries," she is sending the unmistakable message of collective security.
Just as NATO considers an attack on one member an attack on all 28, Clinton was warning North Korea that Washington won't stand idly by if the North acts up again.
South Korea's foreign minister Kim Sung-hwan warned North Korea it faced "consequences" if it engaged in further hostile acts. Although Seoul has made such comments before in recent weeks, standing next to Clinton Kim's comments had added weight.
China's absence from the meeting also spoke volumes, not just about the alliance between the United States, Japan and South Korea, but also about the growing frustration at China's timid stance regarding the North. U.S. officials say the message to China is that its approach to the North Korean issue has failed and that it must step up and exert its considerable influence to pull North Korea back from the brink.
Most importantly, the meeting sought to offer a tight embrace of a jittery South Korean government that has been shaken by the recent shelling of Yeonpyeong and the sinking of its Chenan warship earlier this year. Both attacks caught the South Koreans off guard and cost the government of President Lee Myung-bak dearly in terms of public support and forced the defense minister to resign.
North Korea has shown no indication it's done with its antics, and some experts believe North Korea actually has a carefully mapped-out strategy of aggression to make South Korean vulnerable by hurting its government and its economy.
The three allies Monday agreed North Korea's actions constituted a violation of the 1953 armistice that ended the Korean War. By any other metric, these attacks would be considered acts of war, giving South Korea a case at the United Nations for a Chapter 7 resolution authorizing the use of force in the case of further North Korean aggression.
South Korea has exercised considerable restraint to this point, both in its diplomacy and militarily. But officials worry that restraint is fading fast and that unless tensions calm considerably, South Korea could be pushed to the brink itself, forced to act in the face of another North Korean military provocation.
Between its nuclear arsenal and continued Chinese support, Pyongyang has continued to act as if is untouchable. So far that's has been somewhat true. But officials caution that with tensions on a hair-trigger edge, the potential for a wrong move in this most militarized place in the world is very worrisome.
That's why a steady stream of U.S. officials are headed to Asia -- starting with Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, and followed by a delegation led by Deputy Secretary of State James Steinberg and including Assistant Secretary Kurt Campbell and the White House's point man on Asia, Jeffrey Bader.
The United States wants to send the clear signal to all parties involved that tensions must be diffused immediately, before this dangerous situation evolves into catastrophic consequences for the region.