Top South Korean negotiators, who have recently concluded a renewed accord on ballistic missiles with their U.S. counterparts, are patting themselves on the back over what they regard as a major breakthrough after 11 years of bargaining. They also attribute part of the success to the friendship President Lee Myung-bak has cultivated with U.S. President Barack Obama.

“This is the outcome that resulted from the combination of the best South Korea-U.S. relationship, personal friendship between their leaders, and the trust and partnership between the allies,” said an exuberant Chun Young-woo, Lee’s top security aide. But what came out of the negotiations could be seen either a glass half full or one half empty. The accord on the revision of the Korean-U.S. missile guidelines was nothing to brag out.

If their memory is short, Chun and other South Korean negotiators should be reminded that it has taken 11 years for Seoul to be given the green light to increase the maximum range of ballistic missiles of its own manufacture up to 800 km, from the previous 300 km. Even worse, a missile with the maximum range will have only half the desired payload ― 500 kg.

The maximum range and payload fall far short of what South Korea demanded ― 1,000 km and 1,000 kg ― to counteract North Korea’s missile threats. A range of 1,000 km would be needed to cover any place in the North from South Korea’s southernmost territory. South Korea also believes a minimum payload of 1,000 kg is needed if such a missile is to deliver enough firepower to incapacitate underground North Korean military facilities.

True, you may not get all you want in negotiations. As diplomats often say, it takes two to tango. But the South Korean demands must be considered in the context of growing missile threats from North Korea, which is presumed to have already developed intercontinental missiles, with Alaska within their range.

Washington is reportedly concerned that missiles with a range of 1,000 km and a payload of 1,000 kg in the hands of South Korea could provoke China, Russia and Japan. This argument is hardly convincing. Why should they provoke military powers that have their own intercontinental ballistic missiles? They should be more concerned about a wayward, provocative North that has much more powerful missiles in its arsenal than the defense-minded South.

As a military ally, Washington will have to help South Korea effectively cope with North Korean missile threats, instead of forcing it to defend itself with one hand tied behind its back. It needs to ease the missile development restrictions for the South. The sooner, the better.