Conversation so far:
What is al-Khattab's connection to central asia?
At the age of 18, Khattab left Saudi Arabia to participate in the fight against the Soviet Union during the Soviet invasion of Afghanistan.
What else did he do?
During this time, he permanently incapacitated his right hand and lost several fingers.
What happened after this?
Khattab, while leader of Islamic International Brigade, publicly admitted that he spent the period between 1989 and 1994 in Afghanistan.

Question: When did he enter the Balkans?
Self-contained rewrite: When did al-Khattab' enter the Balkans?