Malaysian Airlines flight MH17 flying from Amsterdam in The Netherlands to Kuala Lumpur in Malaysia was shot down from 33000 feet by a surface to air missile. The missile was launched by terrorists operating inside eastern Ukraine. The terrorists are Russian citizens.
These terrorists receive all their equipment and support from the Russian Federation. Nearly all the terrorists are serving or former members of the Russian FSB, GRU or any number of so called 'elite' units from Russia. The thing they all have in common is that they enjoy killing people.
It is impossible to compare these terrorists to what we normally assume to be terrorists in other parts of the world. They are not like the PIRA in Northern Ireland. These terrorists are equipped with TANKS, HEAVY ARTILLERY, SAM SYSTEMS and other sophisticated military equipment. They are supplied by Russia with everything they need. They are allowed to pass freely across the border between Russia and Ukraine as Russia controls many of the crossing points.
So, it is obvious that we should not be referring to these people as terrorists any longer. They are RUSSIAN citizens. Therefore they are acting on behalf of the Russian Federation.
Russia has declared war on Ukraine but has never made any pubic statement to this effect.