North Korea has unveiled its first operational "tactical nuclear attack submarine," naming it Hero Kim Kun Ok after a historical figure. This submarine, known as Submarine No. 841, is intended to be a significant part of North Korea's naval offensive capabilities. It appears to be a modified Soviet-era Romeo-class submarine acquired from China in the 1970s and subsequently produced domestically. Analysts believe it is equipped with ballistic missiles and cruise missiles due to its design featuring 10 launch tube hatches.

However, experts have raised concerns about the effectiveness of such a submarine in the context of North Korea's overall military strategy. These aging submarines are noisy, slow, and have limited range, making them vulnerable to anti-submarine warfare. South Korea's military also suggests that the submarine is not yet ready for normal operations, and North Korea might be exaggerating its capabilities.

Nonetheless, some experts caution that detecting and destroying submerged submarines, even with limitations, remains a challenging task. North Korea's leader, Kim Jong Un, emphasized the importance of arming the navy with nuclear weapons and promised more underwater and surface vessels with tactical nuclear capabilities.

North Korea's actions are in violation of United Nations Security Council resolutions that ban its nuclear weapons and ballistic missile programs. South Korea and Japan have condemned North Korea's submarine launch as a serious threat to regional security.

The term "tactical" submarine implies that it likely does not carry submarine-launched ballistic missiles (SLBMs) capable of reaching the U.S. mainland but rather shorter-range SLBMs or submarine-launched cruise missiles (SLCMs) for regional targets. The submarine's design features an expanded sail and ten vertical launch tubes, possibly for SLBMs and SLCMs.

It may take some time to evaluate the submarine's operational capabilities fully, and it remains uncertain whether North Korea has developed miniaturized nuclear warheads for these missiles.

North Korea's submarine fleet consists primarily of obsolete Romeo-class submarines, and this new development has been in progress since at least 2016. North Korea aims to bolster its naval forces and possibly build nuclear-powered submarines in the future.

This submarine launch coincides with North Korea's 75th founding anniversary celebrations and reports of Kim planning to meet with Russian President Vladimir Putin to discuss weapons supplies. South Korea has sought China's assistance as a member of the UN Security Council in addressing North Korea's nuclear threat.