Photographic images show the launch tower and what appears to be construction materials on the launch pad, Tim Brown, a senior fellow with GlobalSecurity.org, said Thursday. He speculated that the debris may be there to make the pad appear as though it is still under construction.

“The launch pad appears to be operational,” Brown said.

The satellite company DigitalGlobe of Longmont, Colo., produced the images Wednesday.

North Korea has been quietly building the new facility, which is capable of launching ICBMs, for nearly a decade. It represents a major step forward for its long-range missile program because the facility would allow multiple test flights in a short time, which is difficult at the smaller long-range missile launch site known as Musudan-ni on its east coast.

Analysts believe that Kim Jong-il, whose power base stems from his support for the military, may be using the growing tension to give him greater leverage over power elites at home to nominate his own successor.  It has raised alarm in the region over how far iron ruler Kim, 67 and thought to have suffered a stroke last year, may be prepared to take his latest military grandstanding.

North Korea has asked the country’s main bodies and its overseas missions to pledge loyalty to Kim’s youngest son Kim Jong-un, various South Korean media outlets quoted informed sources as saying. Kim Jong-un, born either in 1983 or early 1984, was educated in Switzerland and intelligence sources have said he appears to be the most capable of Kim’s three known sons.  Very little is known about Kim Jong-un, whose youth is a potential problem in a society that adheres closely to the importance of seniority.

“There is a significant link between North Korea’s recent military provocations and succession issues,” said Lee Dong-bok, an expert on the North’s negotiating tactics.  The succession has been one of the most closely guarded secrets in the highly secretive North.

THE ARSENAL – North Korea has well over 1,000 missiles of various ranges. It has sold missiles and missile technology overseas, with Iran being one of the large buyers. The North has more than 800 ballistic missiles — including 600 Scud missiles of various types and 200 Rodong missiles. A U.N. resolution bans it from launching ballistic missiles.

SHORT-RANGE – North Korea has hundreds of non-ballistic missiles with ranges of 150 km (95 miles) or less. These include surface-to-air and surface-to-ship missiles. It fired a barrage of these missiles last week. There are no international agreements that bar it from test-launching these missiles.

SCUD TYPE – These include the Hwasong-5, with a range of about 300 km and the Hwasong-6, with a range of about 500 km. It first test-fired a Scud-B type missile in April 1984. The North has steadily improved the ability of its Scuds to carry heavier warheads.

RODONG TYPE – The Rodong, first test-fired in 1993 and operationally deployed in 1998, has an estimated range of 1,000 to 1,400 km. It can hit all of South Korea and most of Japan.

IRBM – North Korea recently deployed a new type of mid-range ballistic missile that can travel about 3,000 km (1,865 miles). The unnamed intermediate range ballistic missile (IRBM) has a range that puts U.S. military bases in Guam at risk.

TAEPODONG TYPE – The Taepodong-1 is a multi-stage missile with an estimated range of 2,000 to 2,500 km. It uses liquid fuel and was fired over Japan in 1998.

The Taepodong-2 was first test-launched in July 2006 and flew for about 40 seconds before it blew apart. It is a multi-stage missile with a possible range of 6,700 km. Another version was launched in April and flew about 3,000 km before splashing into the sea. Analysts said that test showed the North had extended the range of its missiles but was still years away from building one that could strike the United States with a warhead.

The Taepodong-X is a solid fuel missile under development with an estimated range of 2,500 to 4,000 km.

North Korea does not have an operational missile that can hit the continental United States.

ACCURACY AND PAYLOAD – Most analysts agree North Korea is some time away from building a nuclear warhead small enough to fit on a missile. The accuracy of the mid- to long-range missiles is also suspect.

(Sources: Center for Nonproliferation Studies, South Korean Defense Ministry, Rand), (Reporting by Jon Herskovitz, Jack Kim and Kim Junghyun, Editing by Dean Yates)

Isozaki said the North’s shortage of oil has largely incapacitated its conventional military, which he said poses “virtually no threat” to neighboring countries although it is the world’s fourth-largest.

If the North were to unleash its military, it would face a much stronger set of opponents than it did in 1950.

South Korea, where military service is mandatory, has roughly 670,000 in its armed forces. The United States has 28,000 troops in Korea, and another 50,000 in Japan.

U.S. fighters can reach North Korean airspace from their Japanese bases in about 30 minutes, and two U.S. navy destroyers are “tethered” to the North, meaning they are either in the Sea of Japan or on call to be there quickly if needed.

The United States also now has a nuclear-powered aircraft carrier permanently based in Japan, and has a squadron of F-22 stealth jets — the most advanced in the Air Force — deployed to the southern island of Okinawa.

But despite all of its bluster, some experts say Pyongyang is playing a calculated game and is aware of the danger to the survival of its own leadership if it goes too far and provokes a full-on response from the much-stronger militaries that surround it.

“The North won’t start a game that it knows it will lose,” said Baek Seung-joo, a North Korea expert at Seoul‘s state-run Korea Institute for Defense Analysis.

He and other experts said North Korea is using the nuclear test to get the international community’s attention and to milk for its domestic propaganda value, instilling its populace with pride in their country’s military might.

North Korea has said it does not fear sanctions, which are being mulled by the U.N. Security Council, and is so isolated already that it is used to fending for itself, although the cost has been deep poverty.

For more than a half century, this divided hamlet has been the front-line of a fragile truce that ended the three-year Korean War. Intimidation has been honed to a fine art here. But while tensions this week rose to their highest level in years, there was an odd sense of calm in the Demilitarized Zone.

Skirmishes have a tendency to escalate quickly in Panmunjom.

An effort by American soldiers to trim a popular tree led to an ax fight with North Koreans in 1976 that left two dead. An attempt by a Russian to defect across the demarkation line in the 1980s sparked an extended shootout.

But no incidents have been reported here recently, despite North Korea‘s nuclear test, a week of missile launchings and repeated tirades from Pyongyang that it will no longer abide by the 1953 accord that ended the war.

“We are always at a high level of readiness, but nothing has changed recently,” said U.S. Army Sgt. Brant Walker, part of the small contingent of U.S. troops that are based along the heavily fortified border. “You wouldn’t think it would be, with North Korea right there, but it’s very relaxed.”

Outside of the Demilitarized Zone, however, concerns swirled around the North as spy satellites spotted signs that it may be preparing to transport a long-range missile to a test launch site, South Korean officials said Saturday.

U.S. Defense Secretary Robert Gates issued his harshest warning to the North since it carried out an underground nuclear test on Monday.

“We will not stand idly by as North Korea builds the capability to wreak destruction on any target in Asia — or on us,” he told a regional defense meeting in Singapore. He said the North’s nuclear program was a “harbinger of a dark future,” but wasn’t yet a direct threat.