Ten years ago this week, I was covering the U.S. military as it began its assault on Iraq.

As I read back over my clips, I see a few sensible warnings about the difficulties ahead. But I owe readers an apology for being wrong on the overriding question of whether the war made sense.

Invading Iraq to topple Saddam Hussein a decade ago was one of the biggest strategic errors in modern American history. We'll never know whether the story might have been different if better planning had been done for "the day after," or the Iraqi army hadn't been disbanded, or several other "ifs."

But the abiding truth is that America shouldn't have rolled the dice this way on a war of choice.

As I think back to the crucible of 2003, two remarks made by Arab friends stand out particularly. One was from a prominent Lebanese Shiite publisher who supported the war, but on the condition that America was resolute enough to finish what it was starting.

"If Rome is strong, the provinces are ready," my friend said.

But Rome wasn't strong enough to prevail. America's military power, awesome as it was, turned out not to be sufficient to impose a settlement in Iraq; and in a grinding war of occupation, all our might could not turn on the electricity in Baghdad or frighten Sunnis and Shiites into cooperating with each other.

Rome was also weak at home, politically: The United States didn't have the stomach for a protracted war that President Bush couldn't explain and the public didn't understand.

The second comment was from a Syrian friend who opposed the war. In 2002, when we first discussed the coming battle, he was reading "The March of Folly," historian Barbara Tuchman's account of epochal policy blunders through history. America was about to make another mistake of historic dimensions, my friend warned.

My friend took me aside after the fighting had been raging for several months. I am still haunted by what he said: "I am sorry for America. You are stuck. You have become a country of the Middle East. America will never change Iraq, but Iraq will change America."

What other lessons should America learn from Iraq? An obvious one is the danger of creating a political vacuum by overthrowing a dictator. The United States dreamed that it would modernize Iraq by toppling Saddam Hussein.

But when we disbanded the nonsectarian army and most of the secular government, Iraqis had nowhere to turn but their most basic ethnic and tribal identities as Sunnis or Shiites, Kurds or Arabs.

Many in the CIA understood the need to keep the Iraqi army and civil service together. That's part of why they clashed so sharply with Donald Rumsfeld's Pentagon and his Iraqi champion, Ahmed Chalabi, who wanted to dismantle the Baath Party, root and branch.

I watched a tiny part of that battle play out one day in April 2003 in a bitter argument on the lawn of Chalabi's headquarters at the Mansour Hunting Club in suburban Baghdad.

The headline on that one was "Bush's confusion, Baghdad's mess."

In the political vacuum we created, Iraq tumbled into the past - pulling a lot of the Arab world with it. That's part of why President Obama has been so careful recently in dealing with Syria: He doesn't want America to make the same mistake twice.

But history is cruel: You can try so hard to avoid an outcome that in your very passivity, you make it more likely. Another lesson is the importance of dignity in the Arab world. Most Iraqis despised Saddam Hussein because, in addition to torturing their sons and daughters, he had taken their dignity.

But many came to loath America, as well, because for all our talk of democracy, we damaged their sense of honor and independence. As the Arab world proves over and over, from Palestine to Benghazi, people who are penniless in terms of material possessions would rather die than lose their sense of honor to outsiders.

A final lesson is the benefit of persistence. George W. Bush made a disastrous mistake invading Iraq in 2003. But having busted up the country, he tried his best to clean up the mess.

By checking the spiraling sectarian killing, the surge of U.S. troops led by Bush and Gen. David Petraeus saved thousands of Iraqi lives. It's one thing that Americans did right in this painful story.