Verdict for attempted arson of a ZSU vehicle

I read a news report about a man in Chernihiv who was sentenced to 5 years for attempting to set fire to a military vehicle, even though he didn't manage to do so because he was spotted and detained. Is merely preparing for such a crime – for example, buying an incendiary substance and photographing the vehicle – really enough to receive a verdict, even if the crime was not fully completed? I am interested in the conditions under which one can be prosecuted specifically for attempted crime if the person was stopped before the act was completed.