A short update on Ukraine and the forces in the Black Sea might be in order, as a number of rumors have been going around the web for the last week.
To begin with, the Ukrainian flagship Hetman Sahaydachniy (U130), a Project 1135.1 Nerei / Krivak III class frigate, was reported to have defected to the Russians. However, this was denied by the Ukrainian authorities, and while passing through the Bosphorus earlier this week the ship was spotted flying a large Ukrainian flag. While pictures can be manipulated, I have yet to see any pictures or reports based on non-Russian sources to support the idea of the flagship switching sides.
Also, there have been reports on the US aircraft carrier USS George H.W. Bush (CVN-77) with its task force heading for, or already being in, the Black Sea. As of Tuesday, the ship was anchored outside Piraeus in Greece, apparently planning on staying there for a few days at least.
Also, while the US recieved permission from Turkish authorities to deploy ships to the Black Sea, the ship(s) in question was not the carrier itself, as it is forbidden to transit the Dardanelles and the Bosphorus due to the Montreux Convention of 1936.
This document might prove rather important if things really heat up in Ukraine (it might also prove to be just an ancient scrap of paper that no-one cares about), so lets restate the basic principles, according to how the Turkish ministry of foreign affairs interprets them:
· Merchant ships may pass freely.
· The rules on warships are different for Black Sea-states (incl. Russia, Ukraine and Turkey) and non-Black Sea states (incl. the USA).
· Only submarines belonging to Black Sea states can pass through the straits, and only for the purpose of moving between their bases and dockyards after they were built or serviced.
· The maximum aggregate tonnage which all non-Black Sea states may have in the Black Sea is 45 000 tons.
· The maximum aggregate tonnage which any one non-Black Sea states may have in the Black Sea is 30 000 tons (note that a Nimitz-class carrier displaces well over 100 000 tons).
· Vessels of war belonging to non-Black Sea states cannot stay more than 21 days in the Black Sea.
· Passages through the Turkish Straits are notified to Turkey through diplomatic channels prior to intended passages.
It is often stated that the convention prohibits the passage of aircraft carriers through the Turkish Straits. This is a slight stretch, as the wording in the convention is “designed or adapted primarily for the purpose of carrying and operating aircraft at sea”, meaning that the ship can be equipped as an aircraft carrier, as long as this is not its primary purpose. Obviously, there are few if any vessel serving as carriers in a secondary role, but by christening their Project 1143 / Kiev class VTOL-carriers as “heavy aviation cruisers”, the Soviets managed to get around the convention and pass through the straits during the Cold War.
As far as I know, this has not been tried since the end of the Cold War, and the Turkish authorities simply state that “Aircraft carriers […] can in no way pass”.
In any case, as noted earlier, the tonnage limit alone prohibits the passage of supercarriers, and any move north by the USS George H.W. Bush would be met by a storm of protests. Exactly which ship(s) the USN plans to deploy to the Black Sea is still open for speculation. My personal guess is that at least one Oliver Hazard Perry class friagte or an Arleigh Burke class destroyer will soon be sent north to show the flag, perhaps through a friendly port visit to Odessa.
Edit (060314 @ 11:16 GMT +2): The news is now out that it is Arleigh Burke class destroyer USS Truxtun (DDG 103) that will go to the Black Sea for “a port visit and routine, previously planned exercises with allies and partners in the region”, all of which were “scheduled well in advance of her departure from the United States.” The allies and partners in question are Romania and Bulgaria.