What geographic features keep Kyrgyzstan and Tajikistan isolated from other countries?

Kyrgyzstan and Tajikistan are both landlocked countries located in Central Asia. They are bordered by Uzbekistan, Kazakhstan, Afghanistan, and China. The two countries are isolated from other countries by the high mountain ranges of the Pamir Mountains, the Tian Shan Mountains, and the Alay Mountains. These mountain ranges form a natural barrier between Kyrgyzstan and Tajikistan and the rest of the world.