Mongolia declared it's independence from Manchurian China in 1921 and created "Drujba" (Friendship in Russian) with Communist Russia. Due to such past events Mongolian people have feud with Chinese people and favorable intention towards Russian people.
Worldwide military mobilization
Country of Mongolia and Armed Forces of Mongolia played minor or supporting role in worldwide military mobilization. There was a separatist movement on western border among Kazakhs which have same origin as people of Kazakhstan resulted in mass immigration of Kazakh people to Kazakhstan. Due to Mongolia's rich resources neighboring China and Russia made annexation attempt on Mongolia but neither ideas were accepted in general public. Mongolian people have favorable intention towards Russia and Russian ideology but not to the level of annexation so as a result Mongolia stayed as independent state to this day.