I'm just speculating here. But Russia's capture and annexation of Crimea is blatantly illegal.
Why can't Ukraine enact a regulation or law imposing a large fee on every civilian ship that enters a Crimean port?
And if the ship owners don't pay for the privilege of using a Ukrainian port, file suit against the ship owners for failing to follow Ukrainian law for using what international law calls a Ukrainian port?
Perhaps ending this bizarrely active "wide ranging treaty of friendship" will pave the way:
The [Ukrainian] Supreme Rada overwhelmingly supported a motion by President Petro Poroshenko not to prolong the treaty when it comes up for renewal in April.
Of course, I think Ukraine should charge Russia rent for the entire peninsula.
I'm just wondering if there is a non-military alternative to an escalating war in Europe.
And a cleaning deposit, of course. It could get messy.