There are many Ukrainians that prefer Russia in the "disputed areas". There were attempts at secession going back to 2005-6 when the pres. election was declared fraudulent.
The Artic Oil shipping route is temporarily open now. But Russia has been using at Sea ship to ship oil transfers to get their crude to China and other markets.
Disrupting that shipping could collapse Russia's economy. That might be a better target. If Putin retreats from Crimea, he will leave it in rubble.
"Russian Oil Transfers at Sea Shift Away From Spanish ...
Bloomberg
https://www.bloomberg.com › news › articles › russia...
Jun 28, 2023 — The transfer of Russian crude between tankers at sea has shifted away from Ceuta, a Spanish enclave in North Africa, amid mounting pressure ...
Russia Is Transferring Millions of Barrels of Oil on Tankers ...
https://www.bloomberg.com › news › articles › russia-...
Jan 25, 2023 — A total of 19 million barrels of the crude will likely get transfered at sea this month and last, according to tanker tracking data compiled by ...
Urals oil tanker transfers ramp up off Greek coast
Reuters
https://www.reuters.com › markets › commodities › urals...
Jun 21, 2023 — Russian Urals deliveries through transfers at sea near Greece's Kalamata port rebounded in June after operations dried up in April as the ..."