＜prologue＞
I started a blog called “The Baby Boomer Generation’s Miscellaneous Blog”（Dankai-sedai no garakutatyou:団塊世代の我楽多（がらくた）帳） in July 2018, about a year before I fully retired. More than six years have passed since then, and the number of articles has increased considerably.
So, in order to make them accessible to people who don’t understand Japanese, I decided to translate my past articles into English and publish them.
It may sound a bit exaggerated, but I would like to make this my life’s work.
It should be noted that haiku and waka （Japanese short fixed form poems） are quite difficult to translate into English, so some parts are written in Japanese.
If you are interested in haiku or waka and would like to know more, please read introductory or specialized books on haiku or waka written in English.
I also write many articles about the Japanese language. I would be happy if these inspire more people to want to learn Japanese.
my blog’s URL:団塊世代の我楽多（がらくた）帳 | 団塊世代が雑学や面白い話を発信しています
my X’s URL:団塊世代の我楽多帳（@historia49) on X
(Reference) Original article in Japanese
・中国とロシアの脅威増大！日本の１２海里以内にある特定海域は廃止すべきか？
1. Chinese and Russian warships pass through the Tsugaru Strait during “joint military exercises.”
On October 18, 2021, a fleet of 10 vessels from the Chinese and Russian navies passed through the Tsugaru Strait, which separates Aomori Prefecture and Hokkaido. Furthermore, according to an announcement by the Joint Staff Office of the Ministry of Defense, this fleet subsequently proceeded into the Pacific Ocean, and on October 21, it was confirmed to have sailed south off the coast of Inubosaki, Chiba Prefecture, and near the Ogasawara Islands of Tokyo. Incidentally, this was the first time that Chinese and Russian naval vessels had simultaneously passed through the Tsugaru Strait.
From an international law perspective, this passage poses no problem. This is because the central part of the Tsugaru Strait through which this fleet passed is considered “high seas,” belonging to no country.
However, it is clear that the aim of this “joint military exercise” by Chinese and Russian warships passing through the Tsugaru Strait was to intimidate Japan in response to the “Japan-U.S. joint military exercises.”
2. Differences between “International Straits” and “Designated Sea Areas” under the International Convention on the Law of the Sea
(1) What are “International Straits”?
International straits, or straits used for international navigation, are defined as “straits where international navigation can be freely conducted within the scope defined by the United Nations Convention on the Law of the Sea.”
Article 37 of Part III, Section 2 of the UN Convention on the Law of the Sea defines them as “straits used for international navigation between the high seas or a part of the exclusive economic zone and other parts of the high seas or the exclusive economic zone.”
(2) What is a “Specific Sea Area”?
Under international law, coastal states can define their “territorial sea” within 12 nautical miles (approximately 22 km) from their baseline (the reference line used when establishing territorial sea and exclusive economic zones). Article 1 of Japan’s domestic law, the “Territorial Sea Law (Law Concerning the Territorial Sea and Contiguous Zone),” also stipulates that “Japan’s territorial sea shall be the area extending 12 nautical miles (omitted) from the baseline.”
However, this does not mean that the width of the territorial sea must be set at exactly 12 nautical miles. There is no problem under international law in defining a narrower territorial sea within that range.
The Japanese government, based on the provisions of Article 2 of the supplementary provisions of the aforementioned Territorial Sea Law, has limited the width of the territorial sea in five straits (Soya Strait, Tsugaru Strait, Eastern Channel of the Tsushima Strait, Western Channel of the Tsushima Strait, and Osumi Strait) to 3 nautical miles (approximately 5.5 km) from the baseline.
(3) Specific sea areas of Japan
In other words, the designated sea areas in Japan refer to the five straits where the width of the territorial sea is limited to 3 nautical miles instead of the usual 12 nautical miles: the Soya Strait, the Tsugaru Strait, the eastern and western channels of the Tsushima Strait, and the Osumi Strait.
At first glance, this could be considered “another name for international straits located within Japan.” However, as will be explained later, strictly speaking, “Japan’s designated sea areas” are not “international straits.”
3. Advantages and Disadvantages of Designating “Designated Sea Areas”
(1) Advantages
① Ensuring free navigation aligns with overall national interests
The Japanese government has traditionally explained why it has gone to the trouble of restricting the width of its territorial sea to establish designated sea areas, stating that “as a maritime nation and an advanced trading country, ensuring the free navigation of merchant ships, large tankers, etc., in straits that are crucial international transportation hubs is necessary from the perspective of overall national interests.”
② Avoids conflict with the “Three Non-Nuclear Principles”
If the entire strait were considered Japanese territorial waters, when warships or submarines carrying nuclear weapons from other countries, including the United States, pass through, nuclear weapons would be temporarily brought into Japanese territory. This would conflict with the “no introduction” aspect of the “Three Non-Nuclear Principles” that the Japanese government adheres to. Therefore, it is thought that a portion of the strait was deliberately left as high seas.
③ Japan’s “Specific Sea Area” Does Not Constitute an “International Strait” as Defined by UNCLOS
The “UNCLOS (United Nations Convention on the Law of the Sea),” which sets out various regulations concerning the ocean, has a provision in Part 3 regarding “straits used for international navigation.” However, Japan’s “Specific Sea Area” is not subject to this provision concerning “straits used for international navigation.”
This is because Article 36 of UNCLOS states that “the provisions of this section shall not apply to straits used for international navigation where there are equally convenient routes in the high seas or exclusive economic zone within the strait, in terms of navigational and hydrographic characteristics.”
Here, “straits used for international navigation” refers to straits connecting areas of the high seas or exclusive economic zones. Furthermore, the provisions of this section do not apply to specific straits whose central portion is part of the high seas. In other words, strictly speaking, the five “specific sea areas” designated by the Japanese government, including the Tsugaru Strait, do not qualify as “international straits” under UNCLOS.
For example, if the entire Tsugaru Strait were to be considered territorial waters, it would become an “international strait” connecting areas of the high seas under UNCLOS. Furthermore, in these “international straits,” instead of the usual “right of innocent passage” within territorial waters, a “right of transit passage” (which offers even greater freedom to the transiting party than the “right of innocent passage”) is granted to vessels navigating these straits, further restricting the rights of the coastal state (in this case, Japan). Under this “right of transit passage,” for example, submarine navigation, which is not permitted within territorial waters, is understood to be permitted. Additionally, while normally the airspace above territorial waters constitutes airspace violation if an aircraft from another country passes over it without the permission of the coastal state, in international straits, freedom of passage over airspace based on the right of transit passage is recognized.
(2) Disadvantages
① Frequent incursions into Japanese territorial waters by Chinese and Russian warships navigating “designated areas” have become commonplace.
② Increased military threats from China, Russia, and other countries near “designated areas” (within 3 nautical miles of the Japanese archipelago).
③ Potential for instigating an invasion of the Japanese archipelago by China, Russia, and other countries.