There have been some interesting developments related to North Korea this week.

The U.S. military is conducting a series of drills with South Korea’s military.  The training is intended to boost tunnel-warfare capabilities.

Hundreds of troops from the U.S. and South Korea conducted a joint training exercise dubbed “Warrior Strike” last week, South Korean military sources told the country’s Yonhap News Agency.

The drill, which lasted four days, saw soldiers from the military unit known as the “Black Jack Brigade” train in a “subterranean tunnel,” according to the division’s Facebook page.

Images posted from the drill showed the soldiers using high-tech equipment, including scoped rifles and night-vision goggles.

The U.S. military has not commented on the specifics of the drill but Lt. Col. Christopher B. Logan told Business Insider that “exercises are vital to the readiness of the U.S. and our allies, and ensure we are ready and trained for combined-joint operations.”

Stars and Stripes had additional details:

On Friday, the Texas-based “Black Knights” from the 1st Battalion, 5th Cavalry Regiment air-assaulted from Black Hawk helicopters to Camp Stanley in pre-dawn darkness, linked up with South Korean forces, and entered the bunker in an exercise dubbed Warrior Strike.

The soldiers negotiated a half-mile long, horseshoe-shaped tunnel and numerous alcoves that look like the sort of place an enemy might hide chemical weapons.

…During the Camp Stanley training, troops were equipped with gear that the Korea-based 2nd Infantry Division has on hand to boost tunnel-warfare capabilities. These include a new radio device — the Mobile Ad Hoc Networking Unit, or MPU5 — which acts as a WiFi-like node and creates a peer-to-peer radio relay, allowing the transmission of text and imagery between troops in the tunnel and to a commander on the surface.

The timing follows reports that North Korea is strapping anthrax to ICBM’s and is testing ways to deliver the biological payload without incinerating the pathogen.

The Hermit Kingdom is beginning experiments to test out if anthrax can endure immense heat and pressure it will have to endure when loaded into an ICBM and launched toward the earth’s atmosphere, Japan’s Asahi newspaper reported, citing an unidentified person connected to South Korea’s intelligence services.

“North Korea has started experiments such as heat and pressure equipment to prevent anthrax from dying even at a high temperature of over 7,000 degrees generated at the time of ICBM’s re-entry into the atmosphere,” the report stated. “In part, there is unconfirmed information that it has already succeeded in such experiments.”

Finally, another North Korean soldier has walked across the border to defect to South Korea. This one arrived uninjured, unlike the soldier who crossed last month with a body full of 5 bullets and worms.

A North Korean soldier defected to South Korea by crossing the border in thick fog, triggering gunfire from both sides this morning.

The ‘low-ranking’ soldier in his 20s was spotted by South Korean soldiers using surveillance equipment as he crossed the land border near Yeoncheon and made his way to a guard post.

There were no shots at the time but about an hour later South Korean troops fired 20 rounds from a K-3 machine gun to warn off Northern guards who approached the border apparently looking for their comrade.

The first defector is slowly recovering and enjoying South Korean girl bands and a lifetime supply of chocolate covered biscuits called Choco-pies.