sentences:  However, following the presidency of Bill Clinton, a change in United States foreign policy was introduced with the presidency of his son George W. Bush and the new Bush Doctrine, who increased military spending in response to the September 11th attacks.In Nicaragua, the Contra War ended after the Sandinista government, facing military and political pressure, agreed to new elections, in which the contras' political wing participated, in 1990.In Angola, an agreement in 1989 met Savimbi's demand for the removal of Soviet, Cuban and other military troops and advisers from Angola.