US nuclear sub makes historic port call in South Korea amid tensions with North

For the first time in four decades, a nuclear-capable US Navy ballistic missile submarine has made a port call in South Korea. 

This move comes shortly after North Korea test-fired a solid-fueled intercontinental ballistic missile. 

The South Korean Defence Ministry announced the arrival of the Ohio-class ballistic missile submarine in the port city of Busan on Tuesday. 

The submarine's presence coincided with the inaugural meeting of the Nuclear Consultative Group (NCG) in Seoul, where Kurt Campbell from the US National Security Council was in attendance. 

The NCG was established by the leaders of the US and South Korea in April to enhance deterrence and response capabilities.

The deployment of the submarine follows a period of heightened tensions on the Korean peninsula. 

North Korea has recently tested what it claims to be an advanced long-range missile and has threatened to shoot down US military reconnaissance aircraft engaged in what it describes as "hostile espionage" activities near its territory.

 In response to the submarine's presence, Kim Yo Jong, sister of North Korean leader Kim Jong Un, stated that it would damage the already fractured lines of communication between the two sides. 

She criticized the NCG for openly discussing the use of nuclear weapons against North Korea and the entry of a US strategic nuclear submarine into Korean Peninsula waters for the first time in over 40 years.

Known as "boomers," each Ohio-class submarine can carry a maximum of 20 Trident II ballistic missiles. 

According to estimates from the Nuclear Threat Initiative at the James Martin Center for Nonproliferation Studies, each Trident missile can carry four nuclear warheads. 

This means that each US ballistic missile submarine could potentially be carrying around 80 nuclear warheads.

The port call was made as part of an agreement between US President Joe Biden and South Korean President Yoon Suk Yeol, following their meeting in Washington in April. 

The "Washington Declaration" included measures aimed at deterring North Korea from launching an attack on South Korea. Biden emphasized the ironclad commitment of the mutual defence treaty and the nuclear deterrent. 

The establishment of the NCG was a result of this meeting, with both allies stating that it would enhance combined deterrence and response posture, contributing to peace and stability on the Korean Peninsula and in the Indo-Pacific region.

However, some analysts argue that the presence of a US Navy ballistic missile submarine in a South Korean port is purely symbolic and diminishes the submarine's stealth capabilities. 

Carl Schuster, former director of operations at the US Pacific Command's Joint Intelligence Center, states that tactically, the submarine's most powerful asset, stealthiness, is diminished.

 The Trident missiles have a range of 4,600 miles, enabling them to hit targets in North Korea from various locations in the Pacific, Indian, and Arctic oceans. Blake Herzinger, a research fellow at the United States Studies Centre, adds that these submarines do not need to be near Korea to reach potential targets. 

One of the key aspects of nuclear deterrence is uncertainty, and a US ballistic missile submarine lurking deep below the ocean's surface and far from North Korea would be difficult to detect. 

On the other hand, a submarine arriving in South Korea on a pre-arranged port visit would be more visible, potentially giving North Korea an advantage if they were planning a surprise strike.

In conclusion, the port call of a US Navy ballistic missile submarine in South Korea marks a significant development in the region. 

It comes amidst heightened tensions with North Korea and aims to enhance deterrence capabilities. 

However, opinions differ on the military value of the submarine's presence in a South Korean port, with some arguing that it diminishes its stealth capabilities. 

Nevertheless, the deployment underscores the commitment of the US and South Korea to maintaining peace and stability on the Korean Peninsula and in the wider Indo-Pacific region.