The article examines the question of the status of ‘little green men’ – Russian soldiers involved in the armed conflict in Ukraine. After the presentation of the facts, the author examines the applicable law and tries to answer the question about the nature of the armed conflict in Ukraine and the status of those taking active part in it. The thesis of the article is the claim that the events in Crimea constitute an occupation and, consequently, international humanitarian law applicable to international armed conflicts applies in this case. In contrast, the armed conflict in eastern Ukraine is at least a non-international armed conflict, to which the common Article 3 and the Additional Protocol II and relevant norms of customary law apply. In situations of doubt as to the nature of an armed conflict, such a conflict should be regarded as an international one and thus the individuals participating in armed conflict, those not participating and those that ceased to participate should be granted prisoner of war status and consequently greater protection resulting from the application of the law of international armed conflicts.