iain duncan smith served in the scottish part of the british army, the scots' guard from 1975 to 1981. he became a conservative party mp at the 1992 general election for the constituency of chingford (called chingford and woodford green from 1997). he became a member of william hague's shadow cabinet in 1997 and became shadow defence secretary in 1999. when hague resigned in 2001, iain duncan smith was elected leader of the conservative party, defeating kenneth clarke and michael portillo. in november 2003, conservative party mps passed a vote of no confidence in iain duncan smith because they believed he could not win the general election. he was replaced by michael howard. after the 2010 general election, iain duncan smith was made the secretary of state for work and pensions. he resigned in march 2016.