Who is President Muhammad Zia ul-Haq from Charlie Wilson's War and what is their importance?

President Muhammad Zia ul-Haq is the leader of Pakistan. He has an intense dislike of the United States and assists Afghanistan in their fight against the Soviets. Zia also helps the CIA, but he forbids US involvement and blocks any Americans from entering Afghanistan. The United States, however, will eventually escalate their involvement, citing oversights of Zia's nuclear program. In the end, he cannot afford to do anything that would cause his country to lose millions of dollars in annual aid.