What did Kyiv do after the Kerch Strait seizure?

What did the Kerch Strait crisis look like on 4 December 2018, nine days after Russian forces fired on and captured three Ukrainian Navy vessels? It was a standoff that had spread from the water into diplomacy, border policy and NATO's northern airspace.

The incident took place on 25 November 2018. The vessels were trying to pass from the Black Sea into the Sea of Azov on their way to the port of Mariupol when the Russian Federal Security Service coast guard opened fire and seized them. It was the first time Russian forces had openly engaged Ukrainian forces in the Russo-Ukrainian War.

A sea under pressure

By 29 November, Ukraine's Infrastructure Minister, Volodymyr Omelyan, said the ports of Berdiansk and Mariupol were effectively blockaded, because Russia was letting no Ukrainian vessels enter or leave the Sea of Azov. President Petro Poroshenko called on NATO to send warships to patrol the sea.

Summit fallout

The crisis also reached the G20 summit in Buenos Aires. On 29 November, while flying to Argentina, US President Donald Trump tweeted that he had cancelled his planned meeting with Russian President Vladimir Putin. He said it was not a good time, since Russia had not returned the ships and sailors to Ukraine. Less than an hour earlier he had said he would probably meet Putin. Kremlin spokesman Dmitry Peskov had said that same day that the meeting was still on.

Measures at the border

On 30 November, Ukraine barred Russian men aged between 16 and 60 from entering the country under martial law. Poroshenko said the ban was meant to prevent the formation of private armies in Ukraine. Russia said it did not plan to retaliate.

Tension in the air

NATO and Russia also met in the skies. The Belgian Air Component said on Twitter that Belgian F-16s, flying in the Baltic region on NATO's Baltic Air Policing mission, had intercepted Russian Flanker jets, allegedly because they had no flight plan.

Taken together, these reports show how one clash at sea in late November 2018 fed into a wider set of disputes: access to Ukrainian ports, a cancelled leaders' meeting, entry restrictions at the border and NATO air patrols.