Mr Rumsfeld has served on the Hoover Institution's board

He will join the Hoover Institution as a distinguished visiting fellow.

In an online petition, protesters described the decision as incompatible with Stanford's ethical values.

Mr Rumsfeld resigned from government in November 2006 after the Democrats won control of Congress amid growing dissatisfaction with the war in Iraq.

He was a key architect of US strategy in its global "war on terror" and in Iraq after the 11 September 2001 attacks on New York and Washington.

More than 2,200 people have so far signed the petition, which describes the appointment as "fundamentally incompatible with the ethical values of truthfulness, tolerance, disinterested enquiry, respect for national and international laws and care for the... lives of others to which Stanford is inalienably committed".

'Marketplace of ideas'

Mr Rumsfeld will join a task force on ideology and terror, the conservative research centre announced earlier this month.

"I appointed him because he has three decades of experience, of incredible public service, especially in recent years as it relates to this question of ideology and terror," Hoover director John Raisian told the New York Times newspaper.

The Hoover Institution on War, Revolution and Peace is engaged in the advanced study of politics, economics and international affairs, according to a statement on its website.

It describes itself as a "prominent contributor to the world marketplace of ideas defining a free society".

Mr Rumsfeld has been involved with the centre since 1989 and has served on its board.

US Secretary of State Condoleezza Rice is also a Hoover fellow.

Ms Rice has said she intends to return to Stanford - where she was also the first female and non-white provost - in 2009.