Donald H. Rumsfeld, Defense Secretary for President Gerald R. Ford and a key architect of the wars in Iraq and Afghanistan when he served in the same role under President George W. Bush, died on Tuesday. He was 88.

The cause of death was multiple myeloma, said a spokesman for the family.

The Middle East wars, America’s longest, came at a huge cost. The U.S. spent an estimated $6.5 trillion on the two invasions and occupations, losing nearly 7,000 U.S. service members in the process. Meanwhile, an estimated 800,000 died in Iraq and Afghanistan, mostly national police, military, civilians, and opposition fighters. The wars also unleashed unrest across the Middle East as the U.S. military fought the Taliban and the Saddam Hussein regime, and then later a number of insurgent groups.

The wars were launched following the 9-11 attacks in an effort to combat terror. The Afghanistan invasion started on October 7, 2001, less than a month after the attacks. It was followed by an invasion of Iraq in March 2003.

Rumsfeld, who served as defense secretary under Bush from 2001 to 2006, has long defended the wars, which has led to the U.S. military fighting for nearly 20 years thus far. He did so even after it became clear that the premise for invading Iraq-- that its president, Saddam Hussein, had weapons of mass destruction-- was false.

Rumsfeld used his 2006 farewell speech at the Pentagon to warn against withdrawing occupying troops. He said that it would show enemies that the U.S. lacked the will or resolve to finish its military mission. “It may well be comforting to some to consider graceful exits from the agonies and, indeed, the ugliness of combat. But the enemy thinks differently,” he said.

Later in his 2011 autobiography he wrote that his decision to invade Iraq “created a more stable and secure world," despite the civil war and sectarian fighting that it spawned.

Rumsfeld was certainly not the only Bush administration official behind the Afghanistan and Iraq wars, but he made the crucial decision to continue it. In December of 2001, he denied a plea by the Taliban to broker a surrender. “I do not think there will be a negotiated end to the situation, that's unacceptable to the United States,” he said at the time.

Rumsfeld was also essential in shaping a new type of military strategy that would subsequently be adopted over the next three administrations: The forever war that plays out in the background of American life, abroad, detached, and easy enough for citizens to ignore as spending and death counts continue to tick upwards.

Instead of publicizing death counts (which Rumsfeld found caused outrage in Vietnam while he was working for the Ford administration as Chief of Staff and later Defense Secretary from 1975 to 1977) he decided against compiling or releasing body counts. He assured the public that he had concrete evidence to support his decisions to invade, when he often didn’t. When pressed, he shrugged off significant events as though they weren’t. After U.S. troops captured Baghdad, he responded to widespread looting with a simple, "stuff happens."

Rumsfeld was also implicated in the creation of secretive detention facilities like Guantanamo Bay which he claimed was full of “committed terrorists,” but also held prisoners for whom there was little concrete evidence of terrorist links. The prison camp, he said, should interrogate detainees with “the use of scenarios designed to convince the detainee that death or severely painful consequences are imminent for him and/or his family.”

Rumsfeld did offer to resign after the revelations of torture and prison abuse at Abu Ghraib in 2004, “These events occurred on my watch as secretary of defense,” Rumsfeld said. “I am accountable for them.” Bush declined his offer to resign, opting to keep him on until the mid-term elections of 2006 after it became clear that the wars were not going well.

Rumsfeld’s impact on U.S. foreign policy will be deeply felt for decades to come and will forever alter the path of this country.

Henry Kissinger, perhaps the nearest contemporary figure to Rumsfeld and longtime White House rival, once clocked Rumsfeld as the most ruthless man he knew. Rumsfeld, he said, was a "skilled full-time politician-bureaucrat in whom ambition, ability and substance fuse seamlessly."

This story was originally featured on Fortune.com