The US Office of the Secretary of the Defense has released its annual report to Congress on North Korea's military, and the findings are chilling. Included in the report are the following three maps, which outline North Korea's military might.

View photos north korea military map More

North Korea's ground forces make up the primary thrust of the rogue nation's military. Nearly 70% of its ground forces are forward deployed to within 100 kilometers (62 miles) of the South Korean border.

The ground forces are a mix of infantry corps, which are predominantly comprised of regular and light-infantry units. In general, these forces are housed in fortified underground facilities facing toward South Korea.

In addition to infantry, the ground corps also has large armor and artillery corps. Although corps make use of old technology, their forward-deployed nature remains a threat to South Korea. North Korea's artillery, in particular, is worrisome as the long-range cannons and rockets are capable of hitting South Korea's capital, Seoul, from over the border in the event of a war.

But aside from North Korea's special forces, its ground forces are generally underfed, ill-equipped, and poorly trained.

View photos Screen Shot 2016 02 23 at 10.04.26 AM More

North Korea's second-largest military branch is its air force. Like Pyongyang's ground forces, these airframes are largely based against the South — 50% of North Korea's air force is within 62 miles of the South Korean border.

Although North Korea maintains a large air force, its fleet is estimated at having 1,300 aircraft, consisting almost entirely of legacy Soviet airframes. Pyongyang's most capable aircraft are MiG-29s that were likely procured in the late 1980s from the Soviet Union.

The hermit kingdom also has a few US-made MD-500 helicopters that were obtained in the 1980s by circumventing export controls that are capable of ground-attack missions. But the majority of North Korea's air assets are aging and the country has taken the route of improving its ground forces and hardening the country against air strikes than trying to modernize its air force.

View photos Screen Shot 2016 02 23 at 10.04.37 AM More

The smallest of the military branches, Pyongyang's navy is also largely based against South Korea, with 50% of the navy's assets within 62 miles of the border. The navy is largely comprised of aging patrol boats, submarines, and air-cushioned hovercraft and amphibious vessels.

Of these assets, North Korea's submarine fleet is the most potentially dangerous. Although extremely old, the fleet of an estimated 70 submarines are capable of hiding around the Korean coast and harassing or possibly sinking South Korean vessels.