Ukrainian filmmaker Oleg Sentsov has been awarded the Sakharov Prize for Freedom of Thought, one of the highest accolades Europe has to offer. The decision has honored his steadfastness in the wake of Russia's annexation of Crimea and recognizes Sentsov's enduring fight for truth. The invasion of the peninsula in 2014 was widely condemned as a violation of international law.

The prize also serves as a reminder that Sentsov is not alone: Almost 70 other Ukrainians have been imprisoned by Russia for political motivations.

Clear condemnation of Crimean annexation

When he was arrested four years ago, Sentsov was a little-known film director, not a household name.

Following his arrest, Sentsov was tried for alleged terrorist activities and received an excessive 20-year prison sentence. It was then that he became a symbol of the victims of the politically motivated Russian judiciary and its targeting of those who criticize the Russian aggression against Ukraine.

Read more: Torture in Russia's prisons becoming 'more sophisticated and brutal'

Sentsov did not allow himself to fall victim to his circumstances. He is well aware that in the eyes of the Kremlin, dissidents like him have no right to exist. In this sense, people who criticize the Russian annexation of the Crimea are also defenders of the right to freedom of expression.

The state of affairs on the Ukrainian peninsula since the annexation prove Sentsov is correct. Especially for the Crimean Tatar minority, as well as many other inhabitants of Crimea who remain loyal to Ukraine, but hardly dare to raise their voices today.

The dissident filmmaker, however, would not remain silent. Even in the Russian penal colony at the Arctic Circle, he continued to condemn the actions of Moscow and its disregard and denial of human rights.

Earlier this year Sentsov resorted to a radical, and likely desperate, means of protest: He went on hunger strike, calling for the release of all Ukrainian political prisoners in Russia. Fortunately, he ended the strike after 145 days.

In the grip of conflict

It is not clear whether Sentsov will ever recover from the consequences of the hunger strike. His friends and relatives fear for his health; they have reported that the period of starvation took a severe toll on his organs. Little is known about Sentsov's present condition — Moscow has remained tight-lipped, even his lawyer and family have barely any access to him. It remains to be seen whether Sentsov will be able to come to Strasbourg in December to accept the Sakharov Prize in person.

The awarding of the prize to Sentsov sends a strong message to the Kremlin; the members of the European Parliament are unequivocally calling for the release of Sentsov and other Ukrainian political prisoners. Such an outcome could be made possible by way of a presidential pardon or a prisoner exchange with Ukraine, but, so far, Russia has shown no willingness to do so.

But Russia is not alone in its action: Ukraine has also imprisoned people on dubious charges. These political prisoners have fallen victim to the Russian-Ukrainian conflict; both sides could seek more humane approaches in their tactics. The fate of Oleg Sentsov is a solemn symbol of this standoff.