Why was the era of mongol dominance so short-lived and what were some of the consequences of its disintegration?

Well the Mongols conquered part of Russia. But they let the Russia princes keep power, and over time the power grew and then the Russians became too powerful and gained control again over their country. Some consequences include , um, declination of Mongol population in Moscow.

By taking sides in local politics in Southeast Asia, the Europans would have been more favored and violence wouldn't have ensued.