Straits, Submarines and Law of the Sea

During peacetime and training missions international law and international relations impact submarine movements in straits and narrows even if secrecy is assumed.

Impacting Russia’s invasion of Ukraine under the 1936 Montreux Convention, Turkey has the responsibility to monitor, regulate, and police the Turkish Straits, which consist of: the Bosphorus, Sea of Marmara and the Dardanelles. https://en.wikipedia.org/wiki/Montreux_Convention_Regarding_the_Regime_of_the_Straits

The Strait of Hormuz is also very topical given attacks against Iran and scope that these may soon prevent tankers from transiting this Strait https://www.tandfonline.com/doi/full/10.1080/00908320.2022.2096158#d1e158 .

On 2/07/2026 5:02 PM Shawn C Co-author of this Submarine and Nuclear Matters blog, made the very interesting points :  

“…I have stated before that the Straits of Malacca are an international passageway and governed under [the United Nations Convention on the Law of the Sea (UNCLOS)] https://www.un.org/depts/los/convention_agreements/texts/unclos/part3.htm )

Only the three littoral states, Indonesia, Malaysia and Singapore can jointly patrol the Straits (the Thais sometimes send a warship for joint patrols), so any country sending warships to unilaterally patrol the Malacca Straits, which lies in Malaysian and Indonesian territorial waters, would be ‘frowned upon’.

No nation can stop a ship who is exercising the right of innocent passage - this is why we can see Russian shadow fleet tankers sailing past Singapore. ( https://www.channelnewsasia.com/singapore/shadow-fleet-vessels-zombie-ships-sanctioned-cargo-oil-russia-iran-singapore-straits-5563491 )

If these ships were to pull out of the international lanes for whatever reason and enter Singapore’s territorial waters, they would immediately be stopped by Singapore’s Police Coast Guard.”

Pete Comment

Other UNCLOS aspects relate specifically to submarines.

Under UNCLOS (Article 20) the right of innocent passage for submarines is strictly regulated due to the potential threat they pose to coastal state security. To exercise innocent passage through a foreign territorial sea, submarines must navigate on the surface and show their flag.

Submerged passage without authorization constitutes a violation of the coastal state's sovereignty. For passage to be considered "innocent," it must not threaten the coastal state's peace, good order, or security, excluding activities like espionage or pollution.

Coastal states can impose restrictions, such as requiring submarines to use specific sea lanes, and can temporarily suspend innocent passage for security reasons.

This differs from "transit passage" through international straits, where submarines are permitted to remain submerged. Failure to comply with these rules can result in the coastal state ordering the submarine to leave its waters. Essentially, a submarine's right to innocent passage within 12 nautical miles of a foreign coast is limited to surfaced navigation.

Main Source: Kazuhiro Nakatani's, Submarines at Oxford Public International Law. last updated July 2008 at https://opil.ouplaw.com/display/10.1093/law:epil/9780199231690/law-9780199231690-e1839 A very comprehensive paper on the subject published under the auspices of the Max Planck Institute for Comparative Public Law and International Law under the direction of Professor Anne Peters (2021–) and Professor Rüdiger Wolfrum (2004–2020).

Future Canadian Submarines' biggest task Monitor approaches to Arctic & other Chokepoints

Map courtesy Canadian Society and History: Geography. See much larger image here.

----------------

From Little-Chemical5006 at reddit on February 10, 2026 at https://www.reddit.com/r/canada/comments/1r04q77/new_submarines_will_require_extra_gear_after/

The new submarines Canada plans to buy will not arrive with all the necessary equipment to operate under Arctic ice, meaning they will require modifications after delivery, the head of the navy says. This is under the Canadian Patrol Submarine Project (CPSP). 

Vice-Admiral Angus Topshee said Canada will need to add under-ice gear to the boats after they arrive, such as upward-facing sonar that can detect and map overhead ice and areas of open water.

“Rather than only being worried about the bottom below us, we’re going to be worried about the ice above us, because the ice is actually less predictable,” Topshee said in an interview.

Topshee also said under-ice operations will not be a significant component of the submarines’ tasks. Instead, their biggest task will be monitoring approaches to the Arctic and other chokepoints.

Canada is seeking up to 12 new submarines and has narrowed the search to two models: one from South Korea and another from a joint German-Norwegian partnership. Ottawa is expected to pick one of these vessels this year.

This would be the largest submarine purchase in Canadian history. It’s being made at a time of heightened anxiety over the country’s sovereignty in the Arctic, as world powers, including the United States, increasingly look north for resources and shipping lanes. Canada is also under pressure to increase its military expenditures in order to hit a new, higher NATO spending target.

Topshee called the needed under-ice operation modifications “relatively simple” to accomplish, but said Canada will proceed carefully on developing its capability in the Arctic environment.

“That’s what we’re going to be targeting: to be able to come up to the surface in basically a crack of open water if we want to,” Topshee said. “Part of ability to operate under there is to be able to return safely to the surface when it’s possible.”

Topshee said the majority of the effort by the new submarine fleet will be monitoring the chokepoints in the Bering Strait, the Gulf of St. Lawrence and the transit between Nova Scotia and Newfoundland, as well as the Juan de Fuca Strait between British Columbia and Washington State, the entrance to the Puget Sound and the approaches to northern Vancouver Island, Prince Rupert, B.C., and Kitimat, B.C.

Topshee said after taking delivery of the submarines, Canada will “start to work toward going under-ice, up into the Arctic, and then developing an actual under-ice capability.”

Topshee said Canada will also have to verify whether any other modifications are necessary because of the frigid temperatures of Arctic waters.

AUKUS Submarines Situation Getting Worse

Since it was announced in 2021 the AUKUS Pillar 1 situation has been getting worse. https://en.wikipedia.org/wiki/AUKUS#Pillar_1_%E2%80%93_Nuclear-powered_submarines

From 2028 [1] US completion rates will actually decline from 1.1 standard Virginias per year to 0.8 larger Virginia Block Vs - making availability for the Australian navy even worse. The US is flat out building Columbia-class SSBNs (the highest USN priority - which is where Australia's gifted AUKUS $Billions are ending up). The main US effort is building Columbias until 2042, [2] with sufficient Virginias only available to send to the Australian navy in the mid 2040s. The UK situation of only one or no Astutes available at any one time, is even worse, as this bodes ill for the Astutes' successor, the SSN AUKUS.

Like the Vietnam War that failed, AUKUS is too big to admit failure - until US withdrawal, or reason, forces Australia to withdraw.

[1]  See USS Oklahoma and USS Arizona, the first Virginia Block Vs. expected to be commissioned in 2028. https://en.wikipedia.org/wiki/Virginia-class_submarine#Boats_in_class

[2]  See “All twelve [Columbias] are expected to be completed by 2042…” https://en.wikipedia.org/wiki/Columbia-class_submarine#Overview

China's New 004 Nuclear Carriers to be larger than Fords

China has a continuous build aircraft carrier program that may be catching up to the US Ford carrier program in quality https://en.wikipedia.org/wiki/Chinese_aircraft_carrier_programme#List_of_carriers

Despite Western criticism (mainly reliance on conventional propulsion) see here and here China’s latest carrier, the Fujian Type 003, appears relatively successful. It boasts the latest functioning electromagnetic (EMALS) CATOBAR system https://en.wikipedia.org/wiki/Chinese_aircraft_carrier_Fujian already used on USS Ford.

The Type 004 is planned to be larger than the Type 003, even 10,000 to 20,000 tonnes larger than a Ford. China has suggested the 004s may use novel TMSR-LF1 https://en.wikipedia.org/wiki/TMSR-LF1 thorium-based molten-salt reactors. This may be a false claim or at least a technical risk, likely to have a PWR backup plan. Construction of the first 004 started in 2024–2025. The large size of a 004 would permit larger, heavier carrier aircraft (like the J-20) with a higher war-load, and longer range than aircraft on Ford carriers.

Along with China’s 3 existing carriers, 6 x 004s in all may be built to give China regional dominance in the Western Pacific by 2035 over the Fords. This is if Fords continue to have global responsibilities or withdraw to a US coastal defensive posture under America First.

US National Security Strategy 24 Jan 2026 bad for Australia

Inspired by Anonymous' questions at 1/24/2026 6:01 PM :

The US NATIONAL-DEFENSE-STRATEGY of January 23, 2026 at https://media.defense.gov/2026/Jan/23/2003864773/-1/-1/0/2026-NATIONAL-DEFENSE-STRATEGY.PDF written by the US "Department of War" is very America First, saying:

“We [the US] will deter China in the Indo-Pacific through strength, not confrontation. We will increase burden-sharing with allies and partners around the world. And we will rebuild the U.S. defense industrial base as part of the President's once-in-a-century revival of American industry.”

There are 15 references to NATO in the Strategy, but no mention of Australia, ANZUS, the QUAD, or even AUKUS. This may mean the US is downgrading age old links and understandings with Australia. The US seems to be implying US allies, including Australia, should shoulder more of the burden against China.

You ask "why are we spending most of our budget on small numbers of costly platforms interchangeable with the USN and USAF" Only with Australian nuclear submarines (used Virginias probably sent to us in the mid 2040s) could our navy move safely and quickly enough to patrol and defend seas between China and Australia as well as the Taiwan Strait.

Until we have Virginias Australia will be weak against Chinese naval movements. This is noting China is likely to have one or more Type 093 or new 095 SSNs in front of any taskforce near Australia.

Greenland: Trump Loses Control of Republicans and of Big Money

 

Here and above uploaded January 18, 2026. 

See NBC News January 21, 2026 report “Markets plunge as Trump reignites fears of a trade war over Greenland” at https://www.nbcnews.com/business/markets/stock-market-trump-tariffs-greenland-rcna254918