Pyongyang has again dangerously raised tensions, this time by attacking a small South Korea island in the first artillery strike since the Korean War. The situation on the Korean Peninsula is tense but unlikely to lead to war. Seoul will be constrained by all the same factors that hindered a strong South Korean response to North Korea’s attack in March on the Cheonan naval ship.

South Korea fears that even a limited retaliatory attack could degenerate into an all-out conflagration. President Lee Myung-bak called for a “stern response” but also took care not to escalate the situation further. As with the Cheonan attack, it shows the limited leverage and options that Seoul and Washington have toward North Korea.

The artillery attack furthers the North’s tactical objectives of asserting sovereignty over the Western Sea Area. But, more importantly, it furthers its strategic goals and is part of a continuing pattern of provocations to force the United States and South Korea to abandon pressure tactics, including sanctions. Similarly, North Korea’s disclosure of a covert nuclear facility is another action to force the U.S. and its allies back to the negotiating table by raising fears of an expanding nuclear arsenal.

It is worrisome, if not frightening, how far Pyongyang is now willing to go to achieve its foreign policy objectives. North Korea appears to have abandoned previously self-imposed constraints on its behavior. Although the new brazenness could be linked to the North Korean leadership succession, it may also reflect growing desperation brought on by deteriorating economic and political conditions.

Pyongyang’s actions are designed to weaken U.S. and South Korean resolve but will likely have the opposite effect. Washington responded to this weekend’s disclosure of a covert uranium enrichment facility by rejecting calls for a hasty return to the six-party talks nuclear negotiations. The U.S. and South Korean governments have properly resisted entreaties to acquiesce to North Korean demands. This, in turn, may very well cause North Korea to do something even more provocative.

China resisted efforts for a U.N. response to North Korea’s blatant act of war in the Cheonan attack, even refusing to accept the evidence of the international investigation team. It is unacceptable for Beijing to continue to take a neutral position or pressure Washington to a premature return to the six-party talks.

Although Seoul will likely exercise restraint in this situation, Pyongyang is venturing into new territory in its actions. North Korea’s willingness to engage in ever more provocative acts has created a growing risk of miscalculation by either side. The Cheonan attack, the revelation of a uranium enrichment facility, and today’s artillery attack shows the previously static situation is unraveling.

Bruce Klingner is a senior fellow at The Heritage Foundation.