Donald Rumsfeld’s downfall is replete with sad ironies.

For a start, he is primarily associated with a cause – the democratization of Iraq – that he never gave much sign of believing in. Far from being a neocon, Rumsfeld remains a traditional Midwestern Republican who was happy to thrash Saddam Hussein but never evinced much enthusiasm for remaking the Middle East. It was no accident that he neglected the kind of post-invasion planning needed to implement the sweeping changes envisioned by his boss, George W. Bush, and his erstwhile deputy, Paul Wolfowitz.

From the day that U.S. troops arrived in Baghdad, Rumsfeld was plotting to pull them out. It was this very resistance to a prolonged and massive troop commitment that probably doomed the mission from the start.

Another irony: Rumsfeld was a micromanager who took a hands-off attitude on the most important issues. He became famous for showering subordinates with memos known as “snowflakes,” and on the eve of the Iraq invasion, he was fiddling with deployment schedules down to the company level. Yet he never accepted responsibility for the biggest decisions made in Iraq. Disbanding the Iraqi army? Talk to Ambassador L. Paul Bremer III. Not sending more troops? See Gens. Tommy Franks and John Abizaid.

A third irony: For a man with abundant experience running large organizations, he proved to be a surprisingly poor manager – one who needlessly alienated generals and congressmen alike with his in-your-face manner.

Given his track record, Rumsfeld’s departure came at least two years too late. Final irony: He might have been removed sooner if a group of retired generals hadn’t called for his head, which seems to have led the stubborn president to keep him on as a symbol of civilian control of the Pentagon.

In fairness, Rumsfeld did make some positive changes: Canceling the Crusader howitzer and Comanche helicopter, both costly relics of the Cold War. Redeploying U.S. forces from Germany and South Korea to areas where they might be needed more. Giving the Special Operations Command greater leeway to chase terrorists around the world. Creating the Northern Command to coordinate homeland defense and empowering the Joint Forces Command to better integrate the services. Reorganizing the Army to make the brigade, rather than the more ponderous division, the “basic unit of action.”

Yet there were sharp limits to his “transformation” agenda. It never touched our most expensive and most dubious weapons systems, such as the F-22 fighter jet and the Future Combat Systems family of armored vehicles. Rumsfeld was so devoted to preserving such programs that he refused to spend money to increase the size of the Army and the Marine Corps, despite mounting evidence that they were too small to handle all the missions thrown their way.

This was a reflection of Rumsfeld’s biggest blind spot: his faith in technology. He came into office vowing to do more with less. This wasn’t a completely crazy conceit – it is possible to do more with less in a conventional conflict. It doesn’t take that many American soldiers to defeat the Iraqi Republican Guard. The problem is what comes next. Cruise missiles and aircraft carriers can’t pacify a country of 26 million people. That requires boots on the ground, and we never had enough.

By asking so much of so few, Rumsfeld brought our ground forces to the breaking point. Recruiting and retention requirements are being met only by lowering standards, raising signing bonuses and issuing “stop loss” orders to keep vital personnel in uniform. Equipment is getting so worn that the Army will need an extra $17 billion this year and the Marine Corps an extra $12 billion for repair and replacement. These soaring costs imperil the “next generation” weapons systems Rumsfeld championed. That will leave Bob Gates with some unpleasant choices as he grapples with his predecessor’s bitter legacy.