Were the Mongols destroyers or connectors of the world?

Both, and historians argue about the balance. In Russia and the Arab world, Genghis Khan is remembered as a savage tyrant, while Western scholarship since the 1990s has begun to reassess the view of him as a barbarian warlord. Both views have evidence. Large areas of Islamic Central Asia and northeastern Persia were seriously depopulated. Estimates of the total deaths under the Mongol Empire run from 30 million to as many as 80 million, and according to some interpretations Genghis's conquests killed about 11% of the world's population.

But the same empire connected the continent. Historians use the term Pax Mongolica, modelled on Pax Romana, for the stabilizing effects of Mongol rule on Eurasia. The Silk Road came under one power, competing tribute gatherers were greatly reduced, and it was commonly said that a maiden bearing a nugget of gold on her head could wander safely across the realm. The Yassa, the Mongol law, is said to have decreed complete religious freedom, and bills of exchange, deposit banking and insurance were introduced to Europe during that peace.

The two sides were linked. The Mongol army reshaped the flow of trade by destroying cities on less important routes, and the end of the Pax Mongolica was marked by the disintegration of the khanates and the Black Death. The numbers are also disputed: Russia may have lost half its people, or only 0.5 million of 7.5 million, depending on whom you read.