Russia was not developed in the 19th century, so why did it occupy so much land?

Russia has carried out large-scale expansion under the leadership of previous emperors and achieved remarkable results. In the 19th century, Russia's industrial revolution began. Slavery under feudal production relations was abolished, and capitalism further developed, providing impetus for Russia's further expansion. Russia was defeated in the Crimean War and its expansion in Europe was frustrated. Instead, it directed its expansion towards Asia. It became invincible and its territory further expanded.

Outer Mongolia became independent at the instigation of the Soviet Union, and China has long recognized it. After the end of the "Cold War", the country began to pursue a "multi-pivot" foreign policy. While maintaining balanced exchanges with China and Russia, it also attached great importance to developing friendly relations with developed Western countries, Asia-Pacific countries, developing countries and international organizations, and strengthened ties with Their cooperation has unswervingly consolidated their country's independence, sovereignty and status in international organizations. Therefore, taking back Outer Mongolia is unlikely. After Russia seized large tracts of land that originally belonged to China, it organized a large number of immigrants to move to these places, and the country has always occupied a strong position in the world. Although China has gradually prospered, it still cannot seek help in the face of Russia, which is undergoing a strong rejuvenation. In order to obtain the large territory previously lost, and in the face of a more powerful United States, we must unite and cooperate with Russia to live in peace.