The UN Security Council failed to reach a consensus on the crisis of the Korean Peninsula on Sunday. A day later, the Republic of Korea (ROK) began a live-firing drill near the border of the Democratic People's Republic of Korea (DPRK), ignoring the latter's warning of counterattack.

Tension has been palpable on the Korean Peninsula since the DPRK and the ROK exchanged fire on Nov 23. The two sides have engaged in skirmishes before but none reached such a level and caused even half as much worry. So what is different this time?

Besides the differences in the domestic situations in the DPRK and the ROK, the greatest cause of concern is the shift in United States' strategy to Asia Pacific.

A series of large-scale US-ROK and US-Japan military exercises in the waters around the Korean Peninsula has strengthened US military presence and aggravated tensions in Northeast Asia.

The joint military drills have had the opposite effect on the DPRK. It has become more adamant because it sees the shows as threats to its survival and security. In a tit for tat, it has announced combat-readiness.

The ROK troops held naval drills in 29 places close to the disputed maritime border in the Yellow Sea on Dec 6. They held another round of maneuvers at 27 places in the Yellow Sea's eastern, western and southern waters from Dec 13 to 17. Before Monday's drills the ROK's military said it will "immediately and sternly" deal with any provocation.

The US and the ROK are adjusting their joint military plans according to the developments on the Korean Peninsula, ignoring the DPRK's warning that the drills are heightening tensions on the peninsula.

The exchange of fire and rising tensions on the peninsula have increased the risk of a full-fledged war, which could break out if the situation is allowed to spiral out of control. In fact, a war could have broken out had China not launched an all-out campaign to defuse tensions on the peninsula.

Developments on the Korean Peninsula affect China in more ways than one. If a war breaks out on the peninsula, China's northeast region will come under direct threat, creating enormous pressure on the country, and damage its strategic environment. It will threaten China's peaceful development, especially the plan for the economic rejuvenation of its northeastern region. Mounting military pressure along the border will compel China to reinforce its strength in border areas to safeguard national security.

To ease tensions on the Korean Peninsula, in fact the whole of Northeast Asia, China views the overall developments from a strategic perspective and has made all-out efforts to restore peace and stability in the region. It urges relevant parties to exercise calm and refrain from taking actions that could worsen the situation and appeals to them to resolve the DPRK nuclear issue through peaceful talks.