Complex sentence: On 7 August 1998, American embassies in Nairobi and Dar es Salaam were bombed under the direction of Osama bin Laden, and all pipeline negotiations halted, as the Taliban's leader, Mullah Mohammad Omar, announced that Osama bin Laden had the Taliban's support.
Split into simpler sentences: On 7 August 1998, American embassies in Nairobi and Dar es Salaam were bombed. The United States alleged that Osama bin Laden was behind those attacks, and all pipeline negotiations halted, as the Taliban's then leader, Mullah Omar, announced that bin Laden had the Taliban's support.