Editing Sea of Azov (section)

===21st century===
In December 2003, Ukraine and the Russian Federation agreed in a [[Treaty Between the Russian Federation and Ukraine on Cooperation in the Use of the Sea of Azov and the Kerch Strait|treaty]] to treat the sea and the Kerch Strait as shared internal waters.<ref>{{Cite web|url=https://www.ecolex.org/details/treaty/agreement-between-the-russian-federation-and-the-ukraine-on-cooperation-in-the-use-of-the-sea-of-azov-and-the-strait-of-kerch-tre-149547/|title=Agreement between the Russian Federation and the Ukraine on cooperation in the use of the sea of Azov and the strait of Kerch|website=www.ecolex.org|access-date=2018-11-27}}</ref><ref>{{cite web|url = http://people.ucalgary.ca/~amcewen/Azov-Kerch.pdf|title = Russia – Ukraine Boundary in the Sea of Azov and Kerch Strait|url-status = dead|archive-url=https://web.archive.org/web/20140514090446/http://people.ucalgary.ca/~amcewen/Azov-Kerch.pdf |archive-date=May 14, 2014 |first = Alec|last = McEwan}}</ref>

In September 2018, Ukraine announced the intention to add [[Ukrainian Navy|navy]] ships and further ground forces along the coast of the Sea of Azov, with the ships based at [[Berdiansk]]. The military posturing was exacerbated following the construction of the [[Crimean Bridge]], which is too low to allow passage of [[Panamax]] ships into Ukraine's port.<ref name="2018-09-24_stratfor">[https://worldview.stratfor.com/article/ukraine-and-russia-take-their-conflict-sea Ukraine and Russia Take Their Conflict to the Sea], [[Stratfor]], 2018-09-24</ref> Late that September, two Ukrainian vessels departed from the [[Black Sea]] port [[Odesa]], passed under the Crimean Bridge, and arrived in [[Mariupol]].<ref>[https://www.ukrinform.net/rubric-defense/2551703-dmytro-kovalenko-commander-of-the-ukrainian-navy-move-to-azov-sea.html Dmytro Kovalenko, commander of the Ukrainian Navy move to Azov Sea], [[Ukrinform]] (4 October 2018)</ref> Tensions increased further after the [[Kerch Strait incident]] in November 2018, when Russia seized three Ukrainian Navy vessels attempting to enter the Sea of Azov.<ref>{{cite news |title=Ukraine's ports partially unblocked by Russia, says Kiev |url=https://www.theguardian.com/world/2018/dec/04/ukraine-ports-partially-unblocked-by-russia-says-kiev |access-date=6 December 2018 |work=[[The Guardian]] |date=4 December 2018 |agency=[[Associated Press]]}}</ref>

Control of the western shore of the Sea is vital to the economy of Ukraine but it is also of immense strategic importance to Russia, as a land route to Crimea as well as it is for passage by Russian marine traffic.<ref>[https://www.mei.edu/publications/russian-dominance-black-sea-sea-azov Russian dominance in the Black Sea: The Sea of Azov], ''[[Middle East Institute]]'', Luke Coffey, September 25, 2020. Retrieved March 23, 2022.</ref>

On December 10, 2021, the Ukrainian Navy announced that Russia had blocked off nearly 70 percent of the Sea of Azov, issuing navigation warnings, ostensibly to conduct artillery fire exercises on the sea ..."near Mariupol, Berdyansk and Henichesk."<ref name=aggression>[https://www.rferl.org/a/ukraine-azov-sea-russia-tensions/31604367.html Ukraine Says Russia Blocking Most Of Sea Of Azov As Tensions Mount Between Kyiv And Moscow], ''[[Radio Free Europe/Radio Liberty]]'', December 11, 2021. Retrieved March 26, 2022.</ref> It raised apprehension regarding a potential Russian invasion since it had begun amassing tens of thousands of troops near the southeast Ukraine border and had begun a propaganda war against the Kyiv government.<ref name=aggression/> The Russians seized three Ukrainian military vessel as the boats were trying to cross the strait, and captured 24 sailors who were finally released after months of negotiations.<ref name=aggression/>

On February 24, 2022, Russian forces began shelling Mariupol at the start of the [[2022 Russian invasion of Ukraine]].<ref>{{cite news|last=Vasovic|first=Aleksandar|date=24 February 2022|title=Port city of Mariupol comes under fire after Russia invades Ukraine|work=Reuters|url=https://www.reuters.com/world/europe/strategic-city-mariupol-wakes-blasts-russia-invades-ukraine-2022-02-24/|access-date=23 March 2022|archive-date=26 February 2022|archive-url=https://web.archive.org/web/20220226011024/https://www.reuters.com/world/europe/strategic-city-mariupol-wakes-blasts-russia-invades-ukraine-2022-02-24/|url-status=live}}</ref><ref>[https://news.un.org/en/story/2022/02/1112662 Ukraine Crisis: Protecting civilians 'Priority Number One'; Guterres releases $20M for humanitarian support]. ''UN News''. 24 February 2022. {{Webarchive|url=https://web.archive.org/web/20220301084123/https://news.un.org/en/story/2022/02/1112662 |date=1 March 2022 }}</ref> By May, with the end of the [[siege of Mariupol]], Russia fully captured the city and blocked off Ukraine's access to the sea by controlling the entire north [[Pryazovia]].<ref>{{cite web|url=https://www.npr.org/2022/05/18/1099885151/mariupol-falls-ukraine-russia-what-it-means |title=Mariupol has fallen to Russia. Here's what that means for Ukraine |website=NPR|date=19 May 2022}}</ref>