WASHINGTON — The United States announced Wednesday that it was speeding the deployment of an advanced missile defense system to Guam in the next few weeks, two years ahead of schedule in what the Pentagon said was "a precautionary move" to protect U.S. naval and air forces from the threat of a North Korean missile attack.
The system called THAAD — for Terminal High Altitude Area Defense — was scheduled for deployment around 2015. The decision to deploy it now was the latest in a series of steps intended to deter the North from either military action or new missile tests and came only hours after North Korean officials blocked South Koreans from crossing the border to enter a jointly operated industrial park that employs roughly 53,000 North Koreans.
The North had threatened the move in reaction to taunts from the South Korean media that Kim Jong Un had cut hot lines and other communications across the border, but did not want to risk one of his most precious sources of hard currency. The border has been sealed before, but the move raised doubt about the future of the last remaining major symbol of inter-Korean cooperation.
Earlier this week, the Defense Department announced that two of the Navy's Aegis-class missile-defense warships were positioned in Pacific waters to watch North Korea. Installing the land-based missile system in Guam will free up the ships, which have radar and interceptor missiles, to be repositioned closer to the North Korean coast.
That would give President Barack Obama a wider range of options if the North Koreans fire their missiles in a test, or at a target.
The last time the United States seriously prepared to shoot down North Korean missiles was the summer of 2006, when Defense Secretary Donald H. Rumsfeld ordered the Army to prepare to intercept a long-range Taepodong missile from its antiballistic missile base in Alaska during a North Korean test. But the North Korean missile broke up in flight.
Last month, as the North escalated its threats, Secretary of Defense Chuck Hagel announced that the United States would bolster long-range ballistic missile defenses in Alaska and California. But that process will take several years; the THAAD is intended to deter a threat to Guam, which is on the outer edge of the North's missile range. The system includes a truck-mounted launcher, interceptor missiles, an integrated fire control system and advanced tracking radar.
Hagel, speaking at the National Defense University in Washington, alluded to North Korea's increased capability in response to a question from his audience.
"They have a nuclear capacity now," he said. "They have a missile delivery capacity now. And so, as they have ratcheted up their bellicose, dangerous rhetoric, and some of the actions they have taken over the last few weeks present a real and clear danger."
Hagel's carefully worded comment about the North's "nuclear capacity" was significant; on Tuesday Secretary of State John Kerry insisted that the United States would never recognize the North "as a nuclear state." The difference pointed to the administration's dilemma: After three nuclear tests, there is no doubt the country can trigger a nuclear explosion, but the United States is adamant that it will not reward the North by accepting its arsenal as a permanent reality.
In recent days the North has said it would never negotiate away its nuclear weapons arsenal, and it has taken steps toward expanding it. It declared it will restart a nuclear reactor that gave it a small stockpile of plutonium; photographs published Wednesday on the website "38 North," which follows North Korean developments, show new construction at the aging reactor, dating back several weeks.
The jointly run industrial complex, in the North Korean town of Kaesong, had continued to operate for days since the North threatened to shut it down. But Wednesday, more than 480 South Koreans who showed up at a border crossing were denied permission to cross, said the Unification Ministry of South Korea, which is in charge of relations with the North.
North Korea promised to allow 861 South Koreans currently staying in Kaesong to return home if they wished, the ministry said. But with no replacements arriving, only 33 immediately decided to return home.
It was not the first time that North Korea had disrupted the park's operation. It blocked cross-border traffic three times in 2009, once for three days, out of anger over joint military drills by South Korean and U.S. troops. That blockade was lifted when the military exercises ended. The current U.S.-South Korean military drills are to continue until the end of April.
Meanwhile, the United States and South Korea are entering the final stretch of long-stalled negotiations over another highly sensitive nuclear issue: South Korea's own request for American permission to enrich uranium and reprocess spent nuclear fuel.
For Washington and Congress, allowing South Korea to develop either the enrichment or reprocessing technologies would mark a rare exception, one that nonproliferation advocates said would set a bad precedent, undermine Washington's global efforts to curb the spread of such activities.
Kerry and his South Korean counterpart, Foreign Minister Yun Byung Se, discussed the long-running South Korean desire in Washington on Tuesday and said they would take it up again when Kerry visits Seoul next week.
Both sides hope for a compromise before Obama and President Park Geun Hye of South Korea are scheduled to meet in Washington in May. Park made winning U.S. concessions on the issue a top campaign pledge for her December election.