They wanted to stop it because they thought it would be bad for the economy.
Mansa Musa was able to bring Islamic culture to Mali by bringing Arab scholars and architects to Mali. Mansa Musa is known as the greatest ruler of his time. He was able to increase the Islamic culture in Africa. He was also called the country's architect. I hope this could help you :)
Im not sure if i have this correct, but, around 1990, communist nationalists in Russia kidnapped Mikeal Gorbichav. This caused Boris Yeltsin to be put into power. With his power, he then dissolved the Soviet Union, and liberated eastern europe. He then saved Gorbichav, but by then, Gorbichav was out of powerless. Now, the Soviet Union is called the Russian Federation, and had adopted free trade.