It isn’t just bluster from the North that worries the South. A quick glance at what Seoul has endured over the last few years easily explains why it would want an official reassurance of the Obama administration’s commitment to its security.

In 2010 Pyongyang torpedoed a South Korean Navy ship, the Cheonan, killing 46 seamen. This was an overt act of war. Later that year, the North attacked Yeonpyeong Island, killing more South Koreans—including two civilians.

After these provocations, Washington sent U.S. ships to participate in a join naval exercise with Seoul. But when China learned that a nuclear carrier—the USS George Washington—was slated to join in the exercise, it lodged strong objections.  The Obama administration promptly cancelled deployment of the carrier.

The military exercises were meant to convey a message that the U.S. stood with its ally. Instead, the message read: The U.S. will defend South Korea, but only so far as it doesn’t cause Washington too much trouble. President Obama didn’t even put North Korea back on the list of state sponsors of terror, a move that would have spoken volumes about American resolve to align itself with the South Koreans.

In the joint communiqué issued at the conclusion of Panetta’s meeting with Kim, the allies affirmed that North Korean "aggression or military provocation is not to be tolerated and that the US and the Republic of Korea [ROK] would work shoulder-to-shoulder to demonstrate our combined resolve." Perhaps in affixing his signature, Panetta meant “starting now,” since the administration did next to nothing in response to two overt acts of war against the South in 2010.

Panetta also reassured his South Korean counterpart of the U.S. “commitment to provide and strengthen extended deterrence for the ROK," including using the U.S. nuclear umbrella, as well as conventional strike and missile defense capabilities. Earlier this month, the ROK and U.S. had announced they would significantly extend the range of Seoul’s ballistic missiles.

No one can blame the South for wanting this, especially if it has begun to doubt the credibility of the U.S. commitment to extended deterrence. It is likely U.S. failure to modernize its nuclear force and the president’s reckless pursuit of a nuclear disarmament agenda does little to relieve this concern, especially when countries like China and North Korea are improving their nuclear programs.

President Obama’s much vaunted “Asia Pivot” must include bolstering the U.S. South Korea ally relationship not just in word but in action. The U.S. should expand deployments of missile defense systems to South Korea. The U.S. should also stop its ideologically driven “Global Zero” agenda, modernize the U.S. force, and consider what the ROK would deem reassuring as it pertains to the U.S. nuclear force. And we should publicly reserve the option of rearming U.S. Navy surface ships regularly cruising the region with short-range nuclear weapons.  This would strengthen the nuclear umbrella and deter North Korean intimidation and aggression.

After all, the perception of credible deterrence—by allies and foes alike—is key to maintaining both stability and nonproliferation.

Doubtless China will object to any strengthening of the U.S. alliance with ROK, just as it has objected to strengthening U.S.-Japan relationship. But squawkings from Beijing should not deter the U.S. from doing what is right

Weakening U.S. relationships with our allies invites more aggression from our shared foes. Strength between allies promotes peace.
Heinrichs is a visiting fellow specializing in national security issues at The Heritage Foundation.