At first, you chould to change "in" (Ukraine Republic), because there isn't Russia (as state) in Ukraine, there are russian citizens (as volonteers) in Ukraine, i recommend use "to" (Ukraine), it will more exactily, moreover if you'll perform.
So, let's start:
1. Stability. Because it prevent trading across and around Ukraine with Russia.
2. Impeding the expansion of NATO. (If you remember with what goals NATO was forming, you'll understand)
3. Keeping (or restoration) economic relations, because some enterprises of Ukraine Republic service(d) russian army.
4. Saving face of important player of the world political arena.
But may be, 4th line is a few mainer and should rise above, but unlikely we somewhen learn it.
In the East of Ukraine and particularly in Crimea, the majority of the population are ethnic Russians. There was a general western migration during the soviet era. Russia's goal is to annex these territories. However, that would be illegal in international law. So Russia's version of what it is doing is that it is assisting the local population in its legitimate right to self-determination. You might have problems explaining why you need to use tanks.
Prevent expansion of EU and Nato. And punish Ukraine for refusing to join Russia.
Ok, Katy, now listen to me - a native Kievaness.
Okraine - is a polish insult that up to 1917 was ascribed to galicia (lviv, ivano-frankivsk, ternopil regions), that belonged to Poland & Austria-Hungary. The rest is NOT okraine. Center/North and South East were called MaloRussia (Kiev, Chernigov, Poltava) and NovoRussia/NovoRossiya (Odessa, Nikolaev, Kherson, Dnepropetrovsk/Ekaterinoslav, Zaporozhje/Aleksandrovsk, Donetsk, Lugansk, Kirovograd/Elizevetgrad) respectively.
Tell your "representatives", that WE - CITIZENS OF RUS' (MALORUSSIA, NOVORUSSIA) ARE WAITING FOR RUSSIAN ARMY TO LIBERATE US FROM ZIO-FASCIST YOKE AND THEIR PUPPETEERS FROM FASHINGTON. Unfortunately, I can't tell you what are the exact Russia's "goals" in FORMER okraine, because nobody knows. It would highly depend on how insane and inhuman are Fashingtonians, jWestern corporatocrats/banksters and their lapdogs in jEU.
If you don't convey them my words, then you're living in a totalitarian police state, where words of Truth are hushed or ignored. While you - sheeple over there - are "fighting" for so-called "freedom" of an artificially created imaginary pseudo-country (on stolen from Russia land) labeled by polish insult, jAmerican mercenaries along with their galician servants are murdering, torturing, raping, bullying my compatriots all over "Ukraine" esp in the South East.
"Protection of Ethnic Russians" - that was Hitlers trick - he was "Protecting Ethnic Germans" when he took lumps of other countries (looking familiar?).
Forward defence to protect themselves from NATO aggression.
