European countries, NATO members and neutral (countries) do not have a sovereign right to formulate their military policies and strategies in relations with Russia. If they still have some chance for manoeuvre in their foreign policy, in military policy they remain led by the US. The US persistently imposes confrontation with Russia on Europe.
Russia does not capture Ukrainians, because the Russian military does not take part in hostilities in the Donbas. The Minsk agreements do not state that Russia is at war with somebody.
This is one of the most common disinformation narratives; that Russia has nothing to do with the war in eastern Ukraine and that there is a “civil war” in Donbas. Read more cases on this narrative here.
There is no exact data on the number of Ukrainians arrested by Russia in the occupied parts of Donbas and in the annexed Crimea. The problem is that Russia and the separatists do not recognise such people as prisoners and qualify their actions as crimes, for example, the now liberated Crimean Oleh Sentsov, who was accused by Russia of "preparing a terrorist act" and illegally sentenced to imprisonment.
According to the Security Service of Ukraine, 227 Ukrainians are still illegally detained in the temporarily occupied territories of Donetsk and Luhansk regions. In addition, another 113 people are illegally detained in Russia and the annexed Crimea, 89 of them are Crimean Tatars. Since 2014, 3,280 Ukrainians have been liberated from Russian prisons and from the occupied territories of Ukraine.