Why did Yeltsin want to dissolve the Soviet Union?

Following the U.S. example of vesting chief of state and chief of government powers in a single individual, Yeltsin was to act as his own prime minister. It was also stated that, mindful of Gorbachev’s fate, he would personally supervise the Defense and Interior ministries and the KGB. In addition, the bureaucracy was to be streamlined.

Explanation:

Yeltsin met secretly with leaders of Ukraine and Belarus and together they agreed to dissolve the Soviet Union. In its place would be a voluntary union, the Commonwealth of Independent States When Gorbachev heard what they'd done, he said "They've begun carving this country like a pie."