REGION IN TURMOIL

U.S. options for N. Korea toughened

Fast retaliation planned with similar intensity

Weapons deployed in the Korean War era are displayed at the Korea War Memorial Museum in Seoul. Amid rising tensions on the Korean Peninsula, there were actions on many fronts to lower the possibility of military conflict between North and South.

ASSOCIATED PRESS

A South Korean soldier closes a military gate in Paju, north of Seoul, on Sunday. South Korean and U.S. officials believe North Korea may be setting the stage for another missile test, possibly as soon as this week.

WASHINGTON — As North Korea hints at new military provocations, the United States and South Korea have drawn up plans to respond more forcefully than in the recent past, but in a limited way intended to prevent an escalation to broader war.

U.S. officials described the new “counter provocation” plan as calling for an immediate but proportional “response in kind” — hitting the source of any North Korean attack with similar weapons.

For example, if the North Koreans shelled a South Korean island that had military installations, as has occurred in the past, the plan calls for the South to retaliate quickly with a barrage of artillery of similar intensity.

Amid the rising tensions, there were efforts on many fronts Sunday to limit the possibility of military conflict.

In an indirect but clear criticism of North Korea, China’s longtime ally, Chinese President Xi Jinping, said in a speech that no country in Asia “should be allowed to throw a region and even the whole world into chaos for selfish gain.”

White House adviser Dan Pfeiffer, appearing on the ABC program This Week, played down the situation as “a pattern of behavior we’ve seen from the North Koreans many times.”

Still, the escalating eeeeeeeetensions were underscored when the commander of U.S. forces on the Korean Peninsula, Gen. James Thurman, abruptly canceled a trip to Washington for congressional testimony and consultations.

So did South Korea’s top commander.

South Korea’s national security director said the North this week might launch one of its new Musudan missiles, a modified version of a missile Russia used for decades aboard its submarines. If so, Pentagon officials said they would be ready to calculate its trajectory within seconds and try to shoot it down if it appeared headed toward impact in South Korea, Japan, or the U.S. territory of Guam.

But they planned to do nothing if it were headed toward open water, even if it went over Japan, as a previous North Korean test did.

The officials doubted the North’s new leader, Kim Jong Un, would risk aiming the missile at the United States or its allies.

President Obama has ruled out striking at the missiles while they are on their launchers — when they are easiest to destroy — unless there is evidence they are being fitted with nuclear warheads, which intelligence officials doubt North Korea yet possesses.

Weapons deployed in the Korean War era are displayed at the Korea War Memorial Museum in Seoul. Amid rising tensions on the Korean Peninsula, there were actions on many fronts to lower the possibility of military conflict between North and South.

The key, then, is how to respond to anticipated North Korean hostilities while keeping the crisis from escalating. “How we carry out a proportional retaliation without triggering a general conflict, or an assault on Seoul, is the hardest part of the problem,” said Gary Samore, who served until last month as Mr. Obama’s director for weapons of mass destruction and arms negotiations. “Everyone is aware there are not big margins for error here.”

Some of the public language from the South Korean government suggests Seoul and Washington may not agree on how far any retaliation should go, although the agreement between the two countries guarantees consultation.

“Overreaction by South Korea is a real risk — and we’re working on that problem,” a senior administration official said.

South Korean President Park Geun-hye, a daughter of a famed South Korean dictator from the Cold War, has indicated she might also go after the North’s command-and-control centers responsible for the provocation.

In the past, classified addendums to the war plan for the Korean Peninsula have not been publicized. So it is notable that agreement on a new plan was publicly disclosed — both to deter the North and to reassure the population of the South.

The nature of the response is critical.

Ordering hostilities short of war in an effort to stage-manage the agenda with Seoul and Washington has been a major part of the playbook used by the past two generations of leaders in the North: rapid escalation of a crisis until the United States and South Korea buy temporary peace with aid or investments.

But some U.S. intelligence officials believe Kim may have more to gain from striking out at his enemies — within reason — to bolster his credentials with his military, still deeply suspicious of his youth and inexperience.

The absence of a clear understanding about when and how to use force on the peninsula reflects, in part, the rapid shifts over 20 years between hard-line South Korean governments and those advocating a “sunshine policy” of reaching out to the North.

Ms. Park was elected on a platform of restarting warmer relations with Kim’s government, but the rise in tensions has sent her to the other extreme.

Under current agreements, the South Koreans remain in command on the peninsula under normal armistice circumstances, but General Thurman, as commander of U.S. and U.N. forces, would assume operational control if war broke out.

The transfer of wartime control is set to transfer to South Korea after 2015.