If this is Mongolia, why are all the signs in Russian?

Whilst I sometimes pride myself on how many countries I've visited or lived in, it's a sign of just how un-worldly I am that I was surprised to find, upon landing for the first time in Ulaanbaatar some months back, that all the signs are in Russian. Which, of course, they're not.  They're in Mongolian, a language that is nothing at all -- not even remotely -- like Russian, nor anything like Mandarin Chinese.  The language of the Mongols shares nothing in common with either it's northern or southern linguistic neighbours.  So, then, why do all the signs in Ulaanbaatar look like they've been ripped off 1970's Moscow store-fronts? The Mongolian language has a rather idiosyncratic historical relationship with writing.  Ghengis Khan was illiterate, himself, because, well, there was no Mongolian writing before him.  During his conquests, however, he encountered this interesting technology by which words could be frozen on paper, and he immediately recognised its value for law-making, governance, and administration.  Not content to adapt the written language of another people, he commissioned a writing system to be developed for the Mongolian language.  The result, based on a Uighur script from what is now western China, was an alphabetic system, meaning that it had different letters for consonants and vowels.  That distinguishes it from so many other Asian languages that are either phonetic, like Japanese hiragana, or symbolic, like Chinese characters and Japanese kanji. It's strikingly beautiful.  To the western eye, it might seem to have visual elements of both Asian writing and Arabic calligraphy.  Although Genghis never did learn to read or write, he vigorously promoted the practice of writing and documentation, which flourished under him, and thereafter throughout the Mongol empire. But none of the signs in Ulaanbaatar are in this beautiful script.  They all look Russian.  Which they're not.  They're Mongolian.  But they're written in the same alphabet as Russian: Cyrillic. Cyrillic isn't nearly as beautiful as Mongolian, but it's readable -- at least the sounds can be made out -- by many more people.  It was introduced into Mongolia in the middle of the 20th century when Mongolia came under the protection (or control) of the Soviet Union.  For the same reason Ghangis wanted a writing system -- ease of administration -- the Soviets imposed their alphabet on Mongolia.  And Mongolians have been writing in Cyrillic ever since. The signs don't make any more sense to a Russian speaker than they do to me, but the Russian has the advantage of knowing roughly what the foreign words sound like. Mongolian sounds are a whole 'nuther story.  It's genuinely hard to describe what Mongolian sounds like to my anglophonic ear without coming across as, at least, condescending and, at worst, insulting.  It's a sound unlike any I've heard before in my life.  I speak a little Chinese, a little Japanese, and smatterings of romance languages.  Mongolian, however, sounds to me like something from another planet.  As well it might, since it was the basis for Star Trek script writers when they came up with the sounds Klingons make.  Think what Klingons might sound like making romantic small talk, and you've got my hearing of Mongolian.