Now that Sweden has been accepted into NATO, the Baltic Sea is internal to NATO because its entire coast consists of NATO countries.

Kremlin spokesman has been reported to say that the RF would "have to take countermeasures" in response.

But my question is how does that change the status of Russia's Baltic Fleet? Russia's only access to the Baltic Sea will be through the Gulf of Finland. The fleet can't be quite renamed "the Finland Fleet."

But more importantly, during peace time, when no maritime laws are violated, will the fleet require NATO command's permission to travel across the Baltic Sea? I am specifically curious about the peace-time maritime law, not the fleet's de facto ability (or lack thereof) to travel in violation of such laws.

  • 41
    This question includes the incorrect assumption that the whole Baltic Sea is internal to NATO. Kaliningrad region is still Russia, and St. Petersburg also!
    – Stančikas
    Commented Jul 12, 2023 at 7:38
  • 3
    It is in a similar (not exactly) vein that the US Navy performs "Freedom of Navigation" flights through the South China Sea. Finland, et al, might decide to call the entire area of the Gulf of Finland their EEZ and attempt to prohibit Russian ships from transiting, but Internationally recognized rights exist which require FoN. Ironically, it was Russia itself which attempted to stop British FoN pathing past the Crimea (?) a few years back.
    – CGCampbell
    Commented Jul 12, 2023 at 13:34
  • 1
    @Stančikas yep, I corrected myself on that assumption in my answer to this question, btw. I still think it's useful to have this question. If I could make this oversight when trying to reason about this situation, then so could others. It's ok to correct wrong assumptions in answers. That's what frame challenges are for.
    – wrod
    Commented Jul 12, 2023 at 17:46
  • The fleet can't be quite renamed "the Finland Fleet." The name of the fleet is completely irrelevant. Putin could rename it "the Great Lakes Fleet" or "the Salton Sea fleet" if he wished to.
    – SJuan76
    Commented Jul 13, 2023 at 12:21
  • @Stančikas, the Baltic Fleet can freely sail between Kaliningrad and St. Petersburg, but the entire Oresund is now NATO waters, cutting them off from the Atlantic Ocean.
    – Mark
    Commented Jul 14, 2023 at 20:05

7 Answers 7


According to United Nations Convention on the Law of the Sea (all states relevant to this question are parties to this treaty), within a state's territorial waters, ships of other countries can claim the right of transit passage - basically, if there's no other practical path through a zone completely within a state's (or several states') territorial waters - an example would be the passage out of the Mediterranean to the Atlantic via the Gibraltar Strait - a ship can pass through as long as it does only that (i.e. no stopping unless absolutely necessary, and no activity that is not necessary for passage). Countries can make regulations on how the transit is made, but these laws cannot have the practical effect of denying, hampering or impairing the right of transit passage to any vessel (article 42).

That said - that concerns only territorial waters. Here's a map of territorial waters in the Baltic sea: Cocco, Emilio & G., Tarlao & V.P., Tynkkinen. (2008). Maritime Safety in the North Adriatic Sea and the Gulf of Finland.

As you can see, territorial waters of Estonia and Finland are not in contact, and a ship could pass to and from Russia through Gulf of Finland without entering territorial waters of any NATO members.

  • 24
    I want to point out that this doesn't address the fundamental flaw in the question: none of the territory is in any way under NATOs control. It's controlled by states that are also part of NATO (but they keep their sovereignity about their borders). So the answer should be: it's controlled by states, not by NATO. The latter has nothing to do with it. (The OP is well aware of this answer though)
    – Mayou36
    Commented Jul 12, 2023 at 13:31
  • is the distance to land counted from the mainland? Because it seems like there are some islands which come much closer than 20km/12mi to the boundary, as drawn.
    – wrod
    Commented Jul 12, 2023 at 18:43
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    @Mayou36 That's not entirely true. A core part of NATO is a military command structure that descends to the tactical level. Right now, there are US, German, British, French, etc. forces in residing Eastern European countries, and regular exercises show multinational forces fighting. Germany holds US nuclear weapons, which they will drop from German planes at US command. NATO is far more closely integrated than a UN or EU where the police stop at the borders.
    – user71659
    Commented Jul 12, 2023 at 20:58
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    @wrod it's counted from the baseline. As the shoreline in the gulf is pretty complex, the states use the straight baseline system to simplify measurements. Note that UNCLOS states (article 7 paragraph 6) that straight baselines system cannot be used to cut off another state's territorial waters from international waters, which probably is the reason why they are drawn like this in Gulf of Finland. Commented Jul 13, 2023 at 3:23

A very complicated bunch of rules, treaties, and precedents.

  • The exit of the Baltic Sea would consist solely of the territorial waters of NATO countries if one goes by the 12-mile rule.
  • Innocent passage is allowed through territorial waters even for foreign warships, as long as they follow the rules.
  • Denmark has made the straits an international waterway and it passed regulations on the transit of foreign warships.
  • Russia has recently held the position that building a bridge over a waterway allows them to stop foreign warships. A similar Danish/Swedish bridge exists. The West protested the Russian interpretation.

In summary, I believe that legally nothing much changes.

Note: As of this writing, I believe that the Swedish accession to NATO has not yet happened, even if it has become more likely.


TL;DR: Nothing changes

The territorial control of waterways during peace time inside the state controlled territory is up to states, and not up to defensive security alliances. So it's up to Sweden to decide.

There seems to be some (conscious?) misunderstanding of NATO here: it's a defensive alliance and it becomes relevant in the case of an attack on a member country. As the OP asked specifically for the peacetime consequences, the answer is simple.

I wanna point out that this was never up for discussion and the OP, most likely, knows the answer very well. The question has only been asked to move this narrative (NATO is an empire) forward by purposefully confusing the two things.

  • 2
    @sfxedit I disagree. It does provide an answer, namely that NATO is irrelevant for peacetime operations, as the OP highlights in the question. Only the countries themselves have a right on the waterways, that has nothing to do with NATO.
    – Mayou36
    Commented Jul 12, 2023 at 14:52
  • 1
    Logically for the OP's premise (e.g. absent treaties and laws mentioned in other answers and comments), a military fleet entering a country's national waters (passing within a dozen miles from shore) makes it look like an act of war, no? That's when the defensive alliance aspect may kick into gear...
    – Jim Klimov
    Commented Jul 12, 2023 at 15:05
  • 2
    @sfxedit This question isn't talking about times of war and the fleet in question is already passing through these areas. This seems like a perfectly reasonable answer to the question.
    – Joe W
    Commented Jul 12, 2023 at 15:43
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    @sfxedit That isn't accurate. Russia has had incursions into almost all of its NATO neighbors airspace without a NATO response. It it almost always the air defense of the country Russia is encroaching that responds. Turkey shot down a Russian plane that entered its airspace. NATO didn't do anything. The UK regularly sends planes to intercept Russian planes near its territory. NATO responded when Russia encroached on Estonian territory. A member state's response is not the same as a NATO response. The original question is flawed, the answer is responding to the question asked.
    – David S
    Commented Jul 12, 2023 at 17:38
  • 2
    @DavidS some of those missions are permanently run under NATO command, see on nato.int: "NATO member countries provide the necessary aircraft and assets for the air policing of their own airspace, under SACEUR direction. Those countries without the necessary means to do so are assisted by other NATO members to preserve the integrity of their sovereign airspace. NATO currently oversees five regional air policing missions."
    – JJJ
    Commented Jul 12, 2023 at 17:53

Looks like I haven't noticed that Russia still has Kaliningrad, which is on the Baltic Sea. So the Sea is not entirely internal to NATO.

And, according to the Wikipedia,

The Baltic Fleet is headquartered in Kaliningrad and its main base in Baltiysk (Pillau), both in Kaliningrad Oblast,

So, perhaps nothing happens since it's still HQ'd in a city with access to the Baltic Sea.

  • It was briefly Polish but was Prussian and German for far longer (although the relationship between the historical region/duchy of Prussia and the German state of Prussia wasn't simple either). So yeah maybe Germany will want to re-conquer it and re-establish 1920s East Prussia.
    – Stuart F
    Commented Jul 12, 2023 at 11:08
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    You also overlooked St. Petersburg.
    – phoog
    Commented Jul 12, 2023 at 11:37
  • 1
    @phoog no, i have not. St. Ptersburg has no coast on the Baltic Sea. It has a cost on the Gulf of Finland, which connects to the Baltic Sea, but not on the Baltic Sea itself.
    – wrod
    Commented Jul 12, 2023 at 17:37
  • 3
    My references all describe the Gulf of Finland as part of the Baltic Sea. Besides, fleets are typically named after the waters they patrol, which may or may not be where they are based. Nobody is claiming that the US naval forces based in Virginia should be called the Chesapeake Bay fleet.
    – phoog
    Commented Jul 12, 2023 at 21:24
  • @phoog that is interesting to learn, but it's still a fact that I haven't overlooked St. Petersburg. I considered it and simply hadn't realized the status of the Gulf of Finland. It does sound like you have discovered something that may be worth putting in an answer. As far as "named for the waters they patrol," since Sweden is joining NATO and Russia is treating NATO as an unfriendly entity, it is feasible that the fleet's ability to patrol Sweden-adjacent waters, during peacetime, may be subject to some adjustment.
    – wrod
    Commented Jul 12, 2023 at 22:27

The United Nations Convention on the Law of the Sea guarantees Russia right to innocent passage. However, as Russia notoriously breaks similar right of Poland to travel through Strait of Baltiysk the thing may become political and Russia's ability to sail through NATO territorial waters might become correlated with ability of non-Russian ships to travel through Strait of Baltiysk.

As for Straight of Baltiysk passage:

Negotiations with the Russian Federation have been being undertaken since 1991. After the negotiations, it was possible to navigate through the strait. However, it was frequently suspended by the Russian Federation for various reasons (often contrary to each other).

Whole document

  • " Russia notoriously breaks similar right of Poland to travel through Strait of Baltiysk" - any sources supporting this claim?
    – Vesper
    Commented Jul 13, 2023 at 6:49
  • en.wikipedia.org/wiki/Strait_of_Baltiysk has at least one source.
    – CGCampbell
    Commented Jul 14, 2023 at 13:01

The Baltic Fleet could still reach the Atlantic

There are a series of rivers, lakes, and canals completely inside Russia that connects the Baltic Sea to the Black Sea:

  • The Volga-Baltic Waterway connects St. Petersburg to Lake Lagoda, then to Lake Onega, then Lake Beloye, and finally to the Rybinsk Reservoir on the Volga River. It's 369 km long.

  • Then take the Volga River from Rybinsk to Volgograd. I don't have the exact distance (web searches want to go by plane or car, not boat), but the whole Volga is 3531 km long, and on a map this segment appears to be at least 75% of that, so let's say 2600 km.

  • The Volga-Don Canal is 101 km long, outside of Volgograd.

  • Following the Don River, the distance from Volgograd to the Azov Sea is about 420 km.

Though the width and depth of this route is not as large as a sea route, there are numerous examples of Russia sending ships from the Baltic Sea to the Black Sea. The Minsk, Kaliningrad, and Korolev are Baltic Fleet landing ships that traveled this route and are now participating in the war in Ukraine. Wikipedia also reports

Analysis in May 2022 suggested that it may be feasible for the Russian Navy even to move its Kilo-class submarines between the Black Sea and the Baltic via the internal waterways.

Once in the Azov Sea, Russian ships can then navigate via the Black Sea, the Turkish Straits, and the Mediterranean to the Atlantic Ocean. This includes passage through Turkish waters, which is governed by the Montreux Convention. It's a loooong detour, but that's not NATO's problem.

That solves the issue of getting warships into or out of Saint Petersburg. However, Kaliningrad would be surrounded by NATO countries.


If Russia starts the "special operation" against Baltic states or say Poland, Sweden as a NATO member surely unlikely to give them safe way over the Baltic sea, regardless if "over transit passage" or otherwise. The options to press on the neutral stance of Sweden are much more limited now. This is, of course, a problem. While the ships still can be brought to Baltic sea over the water passageway inside Russia as another answer states, they will be much less efficient in anything they could assist during the war.

As long as this does not happen, there is no reason why military and other Russian ships could not use existing rules without anything changing.

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