Few Americans have spent more time near the center of power than Donald Rumsfeld.  Now he has written an unflinching memoir of his half-century career, sharing previously undisclosed details that will fascinate readers and force historians to rethink many controversies.

Starting from a middle-class childhood in Illinois, Rumsfeld had a rapid rise that won him early acclaim.   He shows us what it was like growing up during the Great Depression and World War II, going to Princeton on scholarships, serving as a naval aviator, then getting his first political job on Capitol Hill during the Eisenhower administration.  He recalls how he won a seat in the House of Representatives at age thirty and what he experienced as a Republican in Congress during the Kennedy and Johnson years.

We also follow him back to the executive branch as he took on key cabinet positions in the Nixon and Ford administrations, including his service as the youngest-ever secretary of defense, just after the trauma of Vietnam.  And we learn about the challenges he later faced as a CEO in the private sector and during his special assignments for President Reagan, including a face-to-face meeting with Saddam Hussein in 1983.

All of that would have been enough material for a fascinating book.  But as 2001 began, Rumsfeld’s greatest challenges lay ahead of him.  At age sixty-eight he returned to the Pentagon as President Bush’s secretary of defense, with a mandate to transform the military for a new century.  Just nine months later he would confront the worst acts of terrorism in American history, followed by unexpected wars in Afghanistan and Iraq.  And he would be on the firing line for many controversies, from the revelations of abuse at Abu Ghraib prison to the allegations of torture at Guantánamo Bay.

Known and Unknown reveals what happened behind the scenes during the critical moments of the Bush years, as the President’s inner circle debated how best to defend our country.  It is based not only on Rumsfeld’s memory but also on hundreds of previously unreleased documents from throughout his career.  It also features his blunt, firsthand opinions about some of the world’s best-known figures, from Margaret Thatcher to Elvis Presley, from Henry Kissinger to Colin Powell, and about each American president from Dwight D. Eisenhower to George W. Bush.

In a famous press briefing, Rumsfeld once remarked that “there are also unknown unknowns… things we do not know we don’t know.”  His book makes us realize just how much we didn’t know.